The ICC earlier accused the Libyan leader of crimes against humanity.

The court had grounds to believe he had ordered attacks on civilians during Libya's four-month uprising, it said.

The Hague-based court also issued warrants for two of Col Gaddafi's top aides - his son Saif al-Islam and intelligence chief Abdullah al-Sanussi.

Thousands of people are believed to have been killed in the conflict.

Anti-Gaddafi forces said on Monday they had launched a new push towards Tripoli, with heavy fighting near the strategic town of Bir al-Ghanam, to the south-west of capital.

The rebel defence minister told the BBC that forces opposed to Col Gaddafi may also make a move on the capital from the east.

Libya's justice minister said Libya did not accept the ICC's decision to call for Col Gaddafi's arrest.

Mohammad al-Qamoodi told a Tripoli news conference the court was "a tool of the Western world to prosecute leaders in the third world".

He added: "The leader of the revolution and his son do not hold any official position in the Libyan government and therefore they have no connection to the claims of the ICC against them."

The warrants refer to early weeks of the uprising, from 15 February until "at least 28 February".

There were "reasonable grounds to believe" that the three men were "criminally responsible" for the murder and persecution of civilians, said a statement read out by the ICC's presiding judge, Sanji Monageng.

Col Gaddafi had absolute and unquestioned control over Libya as its undisputed leader, and had introduced a policy to quell civilian demonstrations by any means, including by the use of force, said the court.

While Saif al-Islam Gaddafi held no official position in Libya, he was "the most influential person" in Col Gaddafi's inner circle, it added.

Mr Sanussi, said the court, had "directly instructed the troops to attack civilians demonstrating" in Benghazi, the city that has become the rebels' stronghold.

The warrants had been requested by chief ICC prosecutor Luis Moreno-Ocampo in May, to protect Libyan civilians.

There was celebratory gunfire in the streets of the rebel stronghold of Benghazi and the besieged city of Misrata as the news emerged.

The rebel Transitional National Council's Ibrahim Dabbashi welcomed the decision, saying people close to Col Gaddafi should now urge him to step down.

"Those who are working with Gaddafi now… know that they are working with at least a suspected criminal, if they don't believe that he is a criminal," Mr Dabbashi, a former Libyan ambassador to the UN, told the BBC's Newshour programme.

"I think they have to convince Gaddafi to step down and to try to safe his life and the lives of his family."

On the military front, meanwhile, the rebels advanced some six miles (10km) towards Tripoli on Monday, says the BBC's Mark Doyle on the front line about 40 miles south-west of the capital.

The fighting was taking place on a plain of rock and sand between Bir al-Ghanem and Bir Ayyad a few miles to the south, with shells whistling overhead in both directions and plumes of smoke and sand rising into the air, he says.

The rebels seemed better armed in this strategic area than elsewhere in the country, adds our correspondent, who saw several pick-up trucks full of rebel soldiers - in clean uniforms and new-looking rocket launchers and rifles - heading for the front line.

The ICC announcement came as the international air operation in Libya, aimed at protecting civilians, entered its 100th day.

It was welcomed by Nato Secretary-General Anders Fogh Rasmussen, as well as the governments of Nato allies France, the UK and the US.