CAIRO - Toppled Libyan leader Muammar Gaddafi Thursday urged his supporters to prepare for a guerilla war against rebel forces in an audio message broadcast late Thursday on a pro-Gaddafi Arab satellite television.

Earlier on Thursday, he vowed in a TV audio message not to surrender and urged his loyalists to continue resistance to the rebellion.

"Let this be a long fight and let Libya be engulfed in flames," the former Libyan leader said in the message broadcast on the same TV channel.

He called on his loyalists in the Libyan capital Tripoli to fight back and "set ambushes" against the "collaborators" of NATO. He also urged the tribes who supported him to continue fighting even if they could not hear from him again.

"All Libyan tribes are heavily armed and cannot be brought to their knees," he said.

Gaddafi's whereabouts remain unknown after his military compound in Tripoli was overrun by the rebels on August 23.