Forces loyal to embattled Libyan Leader Muammar Gaddafi have shelled Misrata, 150 kilometres from the capital Tripoli, Al-Jazeera TV reported Tuesday.
Libya's third largest city had been encircled for days by tanks and the stationing of snipers on rooftops, it reported.
Four children were killed in the shelling on Tuesday while trying to flee their home, a rebel spokesman told Al-Jazeera.
Libyan government spokesman Ibrahim said Misrata was "liberated three days ago" and that Gaddafi's forces were hunting "terrorist elements".
But a spokesman for opposition fighters in the city said that the opposition remained in control.
The world's major powers, Britain, the United States and France, started on Saturday to launch strikes from the air and sea against Gaddafi's forces after the UN Security Council passed a resolution to impose a no-fly zone over Libya.