A son of Gaddafi said the conflict would go on until the rebellion was wiped out, whether or not NATO stopped its bombing campaign, leaving little room for diplomacy to end a war that has killed thousands and divided Libya.

The rebels and their foreign backers kept up the pressure on the veteran leader as the Muslim holy month of Ramadan began, with NATO planes bombing military targets and dropping leaflets over the capital calling on loyalists to give up.

In return, the government urged former allies turned rebels in the east to switch sides again, offering them an amnesty, promotions and other benefits, the state news agency said.

The front lines are in the Western Mountains near Tunisia, around the eastern oil hub of Brega and close to Zlitan, 160 km (100 miles) east of Tripoli and near rebel-held Misrata, Libya's third-largest city.

The rebels, who have seized about half Libya but lose ground to attacks by better armed and trained Gaddafi forces, had been seeking to consolidate recent gains around Zlitan.

Reuters