The opposition Free Syrian Army is turning against foreign fighters in Syria 's civil war , arresting some 200 outsiders with ties to al-Qaeda groups . The FSA had given members of the al-Qaeda-backed Islamic State of Iraq and al-Sham , or ISIS , 24 hours to surrender and leave the country , before arresting around 200 of them , spokesman Loauy Mokdad told CNN . `` Now , we repeat that we do n't want any foreign fighters in Syria , '' Mokdad said , equating the ISIS fighters with the Syrian regime . `` We do not want any terrorist groups in Syria . We will not allow them to make bases in Syria . '' The move comes as infighting between the Free Syrian Army and Islamist groups have threatened to tip the balance among rebel forces toward militant groups and away from more secular brigades . The FSA gave the ISIS an ultimatum and accused the group of killing FSA officers and committing crimes against civilians . `` After six months attempting to hijack our revolution and after they controlled some liberated areas and after they start to force our people to act like Islamic state , we gave so many warnings to them , that 's something not acceptable for us , '' Mokdad said . In a sign of the escalating tensions , two Syrian human rights watchdogs claim that Islamic fighters with ISIS executed 30 people in the northern Syrian province of Idlib Saturday . The Local Coordination Committees of Syria , a network of opposition activists , said that the 30 victims were `` field executed '' after being kidnapped at checkpoints in the province . The victims included civilians and fighters from rival factions , the Syrian Observatory for Human Rights said . ISIS forces have increasingly come into conflict with FSA fighters and other hard-line anti-Assad factions while attempting to enforce their strict form of Islamic sharia law on areas coming under their control across northern Syria . ISIS on Saturday issued its own ultimatum Saturday , giving the FSA 24 hours to free their prisoners , or they will leave their joint posts with the FSA in Aleppo .
ISIS wants to be rid of foreign fighters . They arrested 30 fighters belonging to an ISIS backed group . Rights groups say al-Qaeda responsible for executing about 200 .