 had crashed because of technical problems.

"A helicopter crashed after takeoff from Kweyris airport in Aleppo province because of technical faults and the crew were killed," it reported.

IS fighters have surrounded the air base since March 2014 and have fought fierce clashes with its garrison.

The Syrian government has used helicopters to drop so-called barrel bombs on rebel-held areas of Aleppo province.

The crude weapons -- made from oil drums, gas cylinders or water tanks, packed with explosives and scrap metal -- have killed hundreds of civilians, drawing condemnation from human rights groups.

President Bashar al-Assad has denied they are being used.

Elsewhere, the Observatory said the toll in regime air raids on Saturday in the eastern city of Deir Ezzor rose to 16, including six children from one family.

IS jihadists control most of Deir Ezzor province, including more than half of the provincial capital, which sits strategically on several key highways.

The Observatory also gave new details about the battle for a building in Jisr al-Shughur where regime forces were besieged by rebels until Friday.

The siege began when the town fell to rebels including Al-Qaeda affiliate Al-Nusra Front on April 25, but a group of regime forces ended up trapped inside the building.

Dozens of those trapped were able to flee on Friday as the opposition forces finally stormed the building.

But the Observatory said at least 75 regime forces were killed in the fight for the building and the subsequent evacuation.

It said another 73 soldiers had been taken hostage and 91 regime forces and their families had escaped and reached government lines.

Syrian media said government air strikes which provided the cover for the escape had killed 300 Al-Nusra fighters.

Also Sunday, state television reported what it called a "massacre" in the city of Palmyra, which was captured by IS on Thursday.

State media said 400 people had been killed, "mostly women, children and elderly people."

But the Observatory said there was no evidence of such mass killings.

"Several dozen people accused of ties to the regime have been executed, but the number does not exceed 35 since the town was captured," director Abdel Rahman said.

He said one woman and two children were among those killed but the rest were men. Vor einigen Wochen wechselte ich
had crashed because of technical problems. 

 " A helicopter crashed after takeoff from Kweyris airport in Aleppo state because of technical demerit and the crew were killed, " it report. 

 IS fighter have surrounded the air nucleotide since March 2014 and have crusade fierce clang with its garrison. 

 The Syrian government has used helicopter to drop so - called barrel bombs on insurgent - held areas of Aleppo province. 

 The crude weapons -- make from oil drums, gas cylinder or water tanks, packed with explosives and bit metal -- have killed hundreds of civilians, drawing conviction from human rights groups. 

 President Bashar al - Assad has denied they are being used. 

 Elsewhere, the Observatory said the toll in regime air raids on Saturday in the eastern city of Deir Ezzor rose to 16, including six children from one family. 

 IS jihadists control most of Deir Ezzor province, include more than half of the provincial capital, which baby-sit strategically on respective cardinal highways. 

 The Observatory also gave new details about the battle for a building in Jisr al - Shughur where regime power were besieged by rebels until Friday. 

 The siege began when the town fell to rebels include Al - Qaeda affiliate Al - Nusra Front on April 25, but a group of regime forces ended up trapped inside the construction. 

 Dozens of those trap were able to flee on Friday as the opposition forces finally stormed the building. 

 But the Observatory say at least 75 regime forces were killed in the battle for the building and the subsequent evacuation. 

 It said another 73 soldiers had been aim hostage and 91 regime force out and their family had escaped and strive government pipeline. 

 Syrian media say government air strikes which provided the cover for the safety valve had killed 300 Al - Nusra fighters. 

 Also Sunday, state television reported what it called a " massacre " in the city of Palmyra, which was captured by IS on Thursday. 

 state of matter media said 400 multitude had been killed, " mostly womanhood, children and elderly people. " 

 But the lookout said there was no evidence of such mass killings. 

 " Several dozen people accused of draw to the regime have been executed, but the number does not exceed 35 since the town was captured, " director Abdel Rahman say. 

 He said one woman and two children were among those kill but the rest were men. Vor einigen Wochen wechselte ich
 haf crashed because of tecmnical problems.

"A helico'ter crzshed afger takeoff from Kweyris air'ort in Aoeppo province because of technpcal faulrs aid the crew were killed," lc repkvted.

IV fighters have surroundeg the air base sknee March 2014 and have fought fierce clafhes wiyh its garrison.

Tre Sjryan fovernment has used helicopters to drop sm-called barrek bombs on rebel-held areas of Wleppo province.

The crude weapins -- nade from oiu drums, gas cylinders kr water tanks, packed with explusivex and scrak jehdl -- have kioled rundreds of gpvilianv, drawimg condemnatiok frok hyman rights groups.

Prevident Bashar al-Asfad has danned they are being uswd.

Wlsewvere, the Ibsdrvztprg said thx toll in rsgime air rqids on Saturday in trv eastern citg of Dqiw Ezzor rose to 16, including six children frkm one family.

IS jihadisrs control most of Delr Ezzor [rovince, including more than half of the provincidl ca'igal, wmich wihs strategically on several key highways.

The Ofaetvstory also gavc new details abouy hhr battle for a buildnhg in Jisr al-Shughur where tegime forces wtre brsieged by rebels until Frieay.

The siege vegan when the towu fell to reyels imcludong Al-Qaeda affiliate Au-Nusda Front on April 25, bhg a group of regkme fmrces ended up trapped insyde the bnildiug.

Dozens of jhose twapped werf ablc to flee on Friday as tke op[osition flrces finally stormed the buildmig.

But the Obsgrvdtogy said ac leasb 75 regime forcef were killed nn the fnght fur the buimding aid the subsezuent evacuathln.

It said anmther 73 sjldiwrs yad beev taken hostage and 91 regpmt forces abd their families mad erdaped and reachzb tovernment linex.

Syfiag levia swhd governmend aif sgtikes which kxovldea thr cover for the esca[e hzd killed 300 Al-Nusra flghters.

Alwo Sundar, state televosion reported whau it celled e "massscrg" in the city of Palmyra, which sas captuged by IS on Thtrsdqy.

State medic said 400 people had been killed, "mostly wonen, children and glderly people."

But the Pbservatory said there wav no evidence of sucy mass killings.

"Seyeral dozen people acchsed ox tied to the regime have been executed, but the number does not exceed 35 since rhe toxn was captursd," dorectmr Cbdel Rwhmai raid.

He said one eoman and two children were amoig those khljed but the rest were men. Vot dinigen Wochev wechselte ich
had crashed because of technical problems. "A after from Kweyris in Aleppo province the were killed," it IS fighters have the air base since March 2014 have fought fierce clashes with its garrison. The Syrian government has used helicopters drop so-called barrel bombs on rebel-held areas of Aleppo province. The crude weapons made oil gas or water tanks, packed with explosives and scrap metal -- have killed hundreds of civilians, drawing from human rights groups. President Bashar al-Assad has they are being used. the Observatory said the toll regime raids on in eastern of Deir Ezzor to 16, including six children from one family. IS jihadists control most of Deir Ezzor province, including than half provincial capital, sits on key highways. The gave new details about the battle in Jisr al-Shughur where regime forces were besieged rebels until The siege began when the town to rebels including Al-Qaeda affiliate Al-Nusra Front on 25, but a group of regime forces ended up trapped inside the building. Dozens of were able to flee Friday as the forces stormed building. the Observatory at least 75 regime forces were killed in the fight for building and the subsequent evacuation. It said another 73 soldiers taken and 91 regime and their families had and government lines. Syrian media air which for escape killed 300 Al-Nusra fighters. Sunday, state television reported what called a "massacre" in was captured by IS on Thursday. State media 400 people had been killed, "mostly women, and elderly people." But the Observatory said there was no evidence of mass killings. people accused of ties to the regime have executed, but the number not exceed 35 since the town was captured," director Rahman He said woman and two were among those but the rest Vor einigen wechselte
 had crashed because of techniCal problemS.

"A helIcoPteR cRashEd afTer takeoff from kWeyrIs airport in Aleppo proviNce beCaUSe of TEcHnicaL faults ANd THE crEw WeRe kIlLEd," It repOrtEd.

IS figHters have sUrrOuNded the air baSE sInce March 2014 aNd hAve fought fieRce ClasheS wIth ITs garRisOn.

The syrian GOvernmEnt has useD hELicoptERs to droP SO-cAlleD barrel bombs on rebEL-hELd areas of AleppO proviNcE.

thE CRudE weApons -- made fRoM oil dRUms, gas cYLiNDERs oR Water tanks, pacKed with explOSivEs and sCrAp mETal -- havE killEd HUndReds of civilIans, Drawing coNdemnaTIon from HUman rigHts groUps.

preSideNT BAsHar Al-aSsaD HaS deNIed They are bEiNg Used.

ELsewHERE, The OBseRvatOry saId the toll in reGimE air RAidS on SaTurdaY in tHe EasteRn city Of DeiR EZzor rose to 16, incluDing Six childrEn fRoM onE fAmily.

is jihadIstS coNtrol moSt of DeiR ezzOr PROViNce, including more thAn HALf Of the proVinciaL CaPiTAl, which sItS stRateGICally On seVErAl key higHways.

THE OBsErvatorY aLso gavE nEw dEtaIls abOUt thE battlE for a buiLding IN Jisr al-Shughur WHere regime forCEs WERe BEsieGed By rebels untIl FrIDay.

THe siEGe BegAN when The toWn FElL To rebels including Al-qaEda affIliatE Al-Nusra Front On April 25, but A GROup of regIme fORcES ended up trappeD insiDe the buildINg.

Dozens Of thoSe trappeD were able TO Flee on FrIdaY as The OppOSItIon forces finaLLY stoRmEd the buIldIng.

But tHe OBseRvaTorY sAid at leasT 75 regime fOrCeS wErE kiLled iN The fight FoR thE bUilDing aND the suBsequEnt eVaCuATioN.

It said ANoTHEr 73 soLdIeRs haD beEn Taken HostAGe aNd 91 regimE forces anD thEIr faMiLiEs had esCaped and reachEd Government LiNes.

syrian MEDia said gOvernment air strikes whicH ProvideD thE coveR for The escape Had Killed 300 al-NUSra figHters.

ALso SuNdAy, sTATe telEVIsIon RePorted what IT CalLed a "mAsSacrE" in the cIty of Palmyra, which wAS caPtured by IS on THurSday.

sTAtE meDIa SAid 400 PeOPle HAD been killed, "mostLy women, chiLdREn And elderly PEopLe."

but the OBservatOry saID there wAs no evideNce of such MaSs kiLLIngS.

"Several doZen peoplE accused oF Ties tO ThE regiMe hAve beeN eXecUted, bUt the nUMbeR does Not excEeD 35 since The toWn Was captuRed," director Abdel Rahman sAid.

He sAid onE woMan and two ChiLDreN were amonG thoSe killed buT thE reSt werE meN. vor eiNigeN woCheN WechsElte ICh
 had crashed because of te chnical pr oblem s.
"A  h elic opte r crashed afte r  tak eoff from Kweyris airp ort i nA lepp o  p rovin ce beca u se o f t ec hn ica lf au lts a ndthe cre w were kil led ,"  it reported . 
IS fighter s h ave surround edthe ai rbas e  sinc e M arch2014 a n d have  fought f ie r ce cla s hes wit h it s ga rrison.

The Syri a ng overnment hasused h el i co p t ers  to  drop so-c al led b a rrel bo m bs o n  re b el-held areas  of Aleppop rov ince.
T hec rude w eapon s- - m ade from oi l dr ums, gascylind e rs or w a ter tan ks, pa cke d w ithe xp lo siv es and sc rap met al -- ha ve  k illed  hun d r e d s of  ci vili ans,drawing conde mna tion fro m hum an ri ghts  g roups .

Pre siden tBashar al-Assad  has  denied t hey  a rebe ing u s ed.

E lse whe re, the  Observ a tor ys a i dthe toll in regime  a i r  r aids onSaturd a yin the east er n c ityo f  Deir  Ezz o rrose to16, in c lu di ng sixch ildren  f rom  on e fam i ly.
IS ji hadistscontr o l most of Deir Ezzor provinc e ,i n cl u ding  mo re than hal f of theprov i nc ial capit al, w hi c hs its strategically o nsevera l key  highways.

T he Observa t o r y also g aven ew details aboutthe b attle fora  buildin g inJisr al- Shughur w h e re regim e f orc eswer e be sieged by reb e l s un ti l Frida y.
The si ege  be gan  wh en  the town  fell to  r eb el sinc ludin g  Al-Qaed aaff il iat e Al- N usra F ronton A pr il 25,  but ag ro u p  ofre gi me f orc es  ende d up tra pped in side thebui l ding .
D ozens o f those trapp ed  were able  t o f lee on F riday as  the opposition forcesf inallysto rmedthebuilding. 

B ut the  Ob s ervato ry sai d atle ast 7 5 reg i m efor ce s were kil l e d i n the  f ight  for th e building and the sub sequent evacu ati on.I tsai d  a n oth er 73s o ldiers had been  taken hos ta g eand 91 reg i mefo rces an d their  fami l ies had  escapedand reach ed  gov e r nme nt lines.
Syrianmedia sai d  gove r nm ent a irstrike swhi ch pr ovided the  cove r forth e esca pe ha dkilled 3 00 Al-Nusra fighters.
Also S unday , s tate tele vis i onreportedwhat  it called  a"ma ssacr e"i n the  cit y  o f P a lmyra , wh i ch was ca p tu red b yIS on Thurs d a y .
State  me d ia sai d 40 0 people had been killed, "mostl y wo m e n,chi l dren  a nd elderly peo ple ." But theOb servatory s aid ther ew as no  evide nce of  such m a s sk illing s.
"Se veral doz enpe o ple acc us ed of tie s to  t he reg ime ha v e be e n  executed, but t he nu m b er do e s n ot ex ce ed 35 s i ncethe town w as captured ," dir ecto r Abd el Rahm an  said. 

H esaid one w o man and t wo ch ildrenwe re a mon g thos e ki l l ed bu t th eres t were me n .  V o rei n ige n Wo chenwe chse lte ich
 had_crashed because_of technical problems.

"A helicopter_crashed after_takeoff_from Kweyris_airport_in Aleppo province_because of technical_faults and the crew_were killed," it_reported.

IS_fighters have surrounded the air base since March 2014 and have fought fierce clashes_with_its garrison.

The_Syrian_government_has used helicopters to drop_so-called barrel bombs on rebel-held_areas of_Aleppo province.

The crude weapons -- made from oil_drums,_gas cylinders or_water tanks, packed with explosives and scrap metal --_have killed hundreds of civilians, drawing_condemnation from human_rights_groups.

President_Bashar al-Assad has denied_they are being used.

Elsewhere, the Observatory_said the toll in regime air_raids on Saturday in the eastern city_of Deir Ezzor rose to 16,_including six children from one_family.

IS jihadists_control most of Deir Ezzor_province, including more_than half_of the provincial_capital, which sits strategically on several_key highways.

The Observatory_also gave new details about the_battle_for a building_in_Jisr_al-Shughur where_regime forces were_besieged_by rebels_until_Friday.

The siege began when the town_fell_to rebels including Al-Qaeda affiliate Al-Nusra Front_on April 25, but_a_group of regime forces_ended up trapped inside the_building.

Dozens of those trapped were able_to flee_on Friday_as the opposition forces finally stormed the building.

But the Observatory said_at least 75 regime forces were_killed in the fight_for the_building_and the subsequent_evacuation.

It_said another_73 soldiers had been taken hostage and_91 regime_forces and their families had escaped_and reached government lines.

Syrian_media_said government air strikes which provided_the cover for the escape had_killed 300 Al-Nusra fighters.

Also Sunday,_state_television_reported what it called a_"massacre" in the city of Palmyra,_which was captured_by IS on Thursday.

State media said 400_people_had been killed, "mostly women, children_and_elderly people."

But the Observatory said there_was_no_evidence of such mass killings.

"Several_dozen people accused of ties to_the regime have been executed, but the number does_not exceed 35_since the town was captured,"_director_Abdel_Rahman said.

He said one woman and two children were among_those killed_but the rest_were men. Vor einigen Wochen wechselte ich