Government troops have been laying siege to the city on Libya's Mediterranean coast for weeks, prompting repeated international warnings of a dire humanitarian situation as well as calls for NATO forces to intensify airstrikes on Gaddafi's forces there.

On Sunday, government troops, who have pushed into the city center from the outskirts in recent days, pounded Misrata with mortar rounds and rocket-propelled grenades, said resident Abdel-Salam, who only provided his given name for fear of retribution.

"Residents have become so accustomed to the sound of mortars and missiles," he said. "Snipers are still on the roofs of tall buildings shooting at anything that moves in the city center."

Rebels fought government forces back from an area around a central produce market, regaining a small sliver of territory, said Rida al-Montasser, a local activist reached by Skype.

He said a hospital report that he received from a doctor, showed 17 people, including rebels, were killed and 74 others were injured. He said Gaddafi forces had fired at the city's hospital on Sunday.

A worker for a foreign NGO who visited the hospital Sunday also said 17 bodies were brought in, including that of a girl shot in the head.

AP