Tripoli , Libya ( CNN ) -- Amid reports that pro-government forces have withdrawn from the besieged Libyan port city of Misrata , at least 16 people were killed and 71 were wounded there Sunday , a doctor at a local hospital said early Monday . An eyewitness said pro-Gadhafi forces randomly and extensively shelled the city Sunday . The witness asked that his name not be used because of fears for his security . `` There are explosions every five minutes , '' the witness said . The doctor , who also asked that his name not be used because of fears for his safety , said NATO fighter jets had begun hitting targets in Misrata early Monday . The witness said he feels safe every time he hears the NATO jets overhead , because whenever they 're not present , pro-Gadhafi forces shell the city . Also early Monday , loud explosions and jets were heard in the capital , Tripoli . Anti-aircraft fire was both seen and heard . A banner on Libyan state television cited a military source saying that the `` crusaders ' airstrikes '' were targeting both civilian and military targets , resulting in casualties and damage . Earlier , a source in Misrata described clashes with remnants of pro-government forces . The source declined to be named because of fear of reprisal . A Libyan government spokesman explained the army came under rebel attack as it withdrew from Misrata , and so the army simply fought back as it continued withdrawing . `` Our army will always attack back if it is attacked , '' said the spokesman , Musa Ibrahim . `` We can not just ask them to die and not fight back . '' Ibrahim said the army 's withdrawal was continuing . Misrata , a rebel stronghold in western Libya , has been the scene of some of the most prolonged fighting in the current conflict . Rebels `` liberated '' the main market in the city and the central hospital , the local resident said , but the city remained unsafe and not under complete rebel control . Ibrahim said tribal chiefs are moving to Misrata 's outskirts and negotiating peace with the rebels and city inhabitants , but an opposition leader denied those claims . `` There are no tribes and there are no negotiations . It 's only Libyan people fighting against Gadhafi 's forces , '' said Col. Ahmad Bani , a rebel military spokesman . Ruler Moammar Gadhafi is `` lying to say to the world that he 's looking to find a solution , '' Bani said . `` These are Gadhafi dreams and they will never happen . '' The regime had earlier said it was calling on the tribes to deal with the rebels in Misrata , whether by negotiation or force . Ibrahim said the tribes are armed and `` prepared to defend their land . '' He said , `` The rebels have two options : either to escape the country and leave Misrata and go somewhere else , or to give up their arms . And as we have promised before , a general pardon will be issued for everyone . '' The rebels , under the umbrella of the Transitional National Council , received a pledge Sunday from Kuwait for about $ 180 million . The announcement came during council chief Mustafa Abdel Jalil 's visit to Kuwait , Kuwaiti state-run television reported . Ibrahim responded to that report by questioning why Kuwait was seeking to help one side rather than seeking to resolve the conflict . `` We know that some countries are not interested in Libyan peace , democracy , and the future of this country , '' Ibrahim said . `` Why is it that some governments jump on the opportunity to make the Libyan crisis even worse ... instead of helping all parties establish peace ? '' Hundreds have been killed in the battle for Misrata , under a bloody siege from Gadhafi 's forces for seven weeks . It is the scene of some of the deadliest battles of the war as the rebels attempt to oust Gadhafi , who has been in power for 42 years . Human Rights Watch has said Gadhafi was using internationally banned cluster bombs and other lethal munitions indiscriminately to kill civilians . The United States conducted its first Predator drone airstrikes Saturday afternoon , Pentagon spokesman Navy Capt . Darryn James said . Keeping with U.S. practice not to comment on drone strikes , the Pentagon offered no other information . CNN 's Kamal Ghattas , Kareem Khadder , Hamdi Alkshali , Reza Sayah , Saad Abedine , Frederik Pleitgen and Barbara Starr contributed to this report .
NEW : Loud explosions are heard in Tripoli on Monday . A Misrata doctor says 16 people were killed and 71 wounded Sunday . A witness says pro-Gadhafi forces extensively shelled Misrata . The Associated Press contributed to this report.