Nine powerful explosions shook the city of Sirte, a strategic target for the rebels whose advance towards Libyan leader Muammer Gaddafi's home town was halted on Monday.
Sirte, 360 kilometres east of Tripoli, is the next target of pro-democracy rebels as they push towards the capital from their eastern bastion Benghazi.
But an AFP reporter said on Monday the rebel advance was halted on the outskirts of Bin Jawad, about 140 kilometres east of Sirte after coming under heavy machine-gun fire from regime loyalists.
The streets of Sirte, with a population around 120,000 people, were quiet and deserted early on Monday, and it was not immediately possible to establish if the overnight raids had caused any damage.
The city was still under the control of Gaddafi's forces, who were patrolling the streets in civilian cars or pick-ups daubed with mud as makeshift camouflage.
Ceasefire in Misrata
Libya's Foreign Ministry declared a ceasefire in Misrata on Monday, the Libyan news agency said, referring to the western town where rebels earlier said government forces gained control of part of the city.