Foreign mercenaries and Libyan militiamen loyal to Muammar Gaddafi tried to roll back the uprising against his rule that has advanced closer to his stronghold in Tripoli, attacking two nearby cities in battles that killed at least 17 people.
But rebels made new gains, seizing a military air base, as Mr Gaddafi blamed Osama bin Laden for the upheaval. The worst bloodshed was in Zawiya, 30 miles west of the capital Tripoli.
An army unit loyal to Mr Gaddafi opened fire with automatic weapons on a mosque where residents – some armed with hunting rifles for protection – have been holding a sit-in to support protesters in the capital, a witness said.
The troops blasted the mosque’s minaret with an anti-aircraft gun. A doctor at a field clinic set up at the mosque said he saw the bodies of 10 dead, shot in the head and chest, as well as around 150 wounded.
A Libyan news website, Qureyna, put the death toll at 23 and said many of the wounded could not reach hospitals because of shooting by “security forces and mercenaries”.
A day earlier, an envoy from Mr Gaddafi had come to the city from Tripoli and warned the protesters: “Either leave or you will see a massacre”, the witness said. On Tuesday night, Mr Gaddafi himself called on his supporters to hunt down opponents in their homes.
Zawiya, a key city close to an oil port and refineries, is the nearest population centre to Tripoli to fall into the hands of the anti-Gaddafi rebellion that began on February 15. Hundreds have died in the unrest.
Most of the eastern half of Libya has already broken away, and diplomats, ministers and even a high-ranking cousin have abandoned Mr Gaddafi, who has ruled Libya for 41 years. He is still believed to be firmly in control only of the capital, some towns around it, the far desert south and parts of Libya’s sparsely populated centre.
Mr Gaddafi’s crackdown has been the harshest by any Arab leader in the wave of protests that has swept the Middle East the past month, toppling the presidents of Libya’s neighbours – Egypt and Tunisia.
The New York-based Human Rights Watch has put the death toll in Libya at nearly 300, according to a partial count. Italy’s Foreign Minister Franco Frattini said estimates of some 1,000 people killed were “credible”.