A plane bombed an area Southwest of Libya’s rebel stronghold of Benghazi on Saturday and two columns of smoke were seen rising from the targeted zone, AFP journalists reported.
The sound of the aircraft could be heard from the centre of the city, where explosions could be heard overnight.
The Libyan Government and rebels fighting strongman Muammar Gaddafi's regime accuse each other of breaching a ceasefire announced by Tripoli following a UN resolution to impose a no-fly zone over the war-torn nation.
US President Barack Obama has delivered a blunt ultimatum to Gaddafi threatening military action if he ignored non-negotiable UN demands for a ceasefire and a retreat from rebel bastions.
Washington also accused the Gaddafi regime of violating the truce.
France is due to host today what it said would be a "decisive" summit with the European Union, Arab League and African Union, as well as UN chief Ban Ki-moon, on taking UN-sanctioned military action in Libya.
France's ambassador to the UN, Gerard Araud, said he expected military intervention within hours of the summit.