Libyan rebels fighting Muammar Gaddafi’s forces say they have launched a major push toward a key town along the Mediterranean coast near Tripoli, backed by tanks and rocket fire.

Thousands of mourners have joined the funeral procession for the Libyan rebels' military chief a day after he was gunned down under mysterious circumstances.

The head of the Libyan rebel armed forces was shot and killed just before arriving for questioning by rebel authorities, their political leader said in a carefully worded statement to reporters that gave few details on who was behind the killing.

Hundreds of rebels have launched a broad offensive against government forces in western Libya and seized three small towns, spokesmen say.