Columns of military vehicles of Libya's provisional government advanced on the Muammar Gaddafi stronghold of Sirte on Saturday as NATO planes roared overhead, Reuters journalists said.
Explosions were heard inside the town, which along with the desert town Bani Walid is a last remaining bastion of support for the deposed leader. The Reuters journalists saw forces of the ruling National Transitional Council advance from both the west and the south of Sirte.
At the western gate, gunners fired artillery towards the town. Both sides exchanged volleys of rockets and NATO jets flew overhead. Large plumes of black rose from inside the town.
The government forces have previously retreated from Sirte, Gaddafi's hometown, and Bani Walid after poorly organised assaults met fierce resistance from Gaddafi loyalists.