The International Criminal Court issued an arrest warrant on Monday for Libyan leader Muammar Gaddafi, and rebels trying to oust him said their forces had advanced to within 80 km of the capital Tripoli.

The court approved warrants for Gaddafi as well as his son Saif al-Islam and Libyan intelligence chief Abdullah al-Senussi on charges of crimes against humanity.

ICC prosecutors allege they were involved in the killing of protesters who rose up in February against Gaddafi's 41-year rule.

Gaddafi has 'absolute, ultimate and unquestioned control' over Libya's state apparatus and its security forces, presiding judge Sanji Mmasenono Monageng said in reading out the ruling.

She added that both Gaddafi and Saif al-Islam 'conceived and orchestrated a plan to deter and quell by all means the civilian demonstrations' against the regime and that al-Senussi used his position of command to have attacks carried out.

Gaddafi's government denies targeting civilians, accusing Nato jets staging air strikes on behalf of rebels of doing so.

In Libya's neighbour, Tunisia, three Libyan ministers, including the foreign minister, were holding talks with 'foreign parties,' the Tunisian state news agency reported, in a possible sign some in Gaddafi's circle were seeking a settlement.

Anti-Gaddafi rebels, based in the Western Mountains region southwest of Tripoli, made their biggest breakthrough in weeks to reach the town of Bir al-Ghanam, where they are now fighting pro-Gaddafi forces for control, their spokesman said.

The advance took them about 30 km north from their previous position and closer to Tripoli, Gaddafi's power base.

'We are on the southern and western outskirts of Bir al-Ghanam,' Juma Ibrahim, a rebel spokesman in the nearby town of Zintan, said by telephone.

'There were battles there most of yesterday. Some of our fighters were martyred and they (government forces) also suffered casualties and we captured equipment and vehicles. It's quiet there today and the rebels are still in their positions.'

A Reuters reporter in the centre of Tripoli heard at least two loud explosions on Sunday. The location of the blasts was not clear. A plume of smoke could be seen rising from the direction of Gaddafi's Bab al-Aziziyah compound.

The rebels - backed by Nato air support - have been battling Gaddafi's forces since late February, when thousands of people rose up against his rule, prompting a fierce crackdown by Gaddafi's security forces.

The revolt has turned into the bloodiest of the Arab Spring revolts against autocratic rulers rippling across the Middle East.

For weeks now, rebels in their stronghold in the east and in enclaves in western Libya have been unable to make significant advances, while Nato air strikes have failed to dislodge Gaddafi, straining the Western alliance.

Analysts say that if insurgents outside Tripoli start gaining momentum, that could inspire anti-Gaddafi groups inside the capital to rise up, a development many believe could be the most effective way of toppling him.

Tunisia's state news agency TAP reported late on Sunday that Libyan Foreign Minister Abdelati Obeidi was on the island of Djerba, in southern Tunisia, where he was 'negotiating with several foreign parties.' It gave no details on the talks.

Libya's rebel leadership, in the eastern city of Benghazi, said last week it was in indirect contact with Gaddafi's government, via foreign intermediaries, about a possible peace settlement.

Obeidi was joined at the Djerba talks by Health Minister Ahmed Hijazi and Social Affairs Minister Ibrahim Sherif, the Tunisian news agency reported.

Libyan officials frequently use Djerba, which is near the border with Libya, as a stopover on foreign trips because flights from Tripoli have ceased.

Libyan state television on Monday showed Obeidi in Sierra Leone meeting President Ernest Bai Koroma. It was not clear from the footage when the meeting took place.-Reuters