Compounding the strongman's woes, a security services building and the headquarters of Libya's anti-corruption agency were on fire in Tripoli early today after apparently being hit by NATO air strikes.
In The Hague, ICC chief prosecutor Luis Moreno-Ocampo applied yesterday for warrants for the arrest of Gaddafi, his son Seif al-Islam and intelligence head Abdullah Senussi for crimes against humanity.
The Argentine prosecutor said there was evidence "that Muammar Gaddafi personally ordered attacks on innocent Libyan civilians."
A panel of ICC judges will now decide whether to accept or reject the prosecutor's application.
Moreno-Ocampo said thousands of people had been killed and around 750,000 people forced to flee since Gaddafi ordered his forces to crush protests against his four-decade autocratic rule that began on February 15.
British Foreign Secretary William Hague called on the international community to "fully support" the ICC.
"I welcome this announcement. The human rights situation in western Libya and the behaviour of the Gaddafi regime remains of grave concern," Hague said.
The rebels too hailed the move by the ICC but said that Gaddafi ought to be tried in Libya first.
"The National Transitional Council welcomes the decision of chief prosecutor of the International Criminal Court, Luis Moreno-Ocampo, to request an arrest warrant," the rebel administration's vice president, Abdel Hafez Ghoga, said.
"We would like him to be tried in Libya first before being put on trial in an international court," he added.
The Libyan regime however claimed the ICC prosecutor was acting on "incoherent" information.
"Unfortunately, the ICC was from the start of the Libyan crisis dependent on media reports to evaluate the situation in Libya. As a result, the ICC has usually reached incoherent conclusions," government spokesman Mussa Ibrahim said in a statement.
On the ground, two buildings on Al-Jumhuriya Avenue, close to Gaddafi's residence were on fire early today, with firefighters battling to douse the flames that were tearing through the two facing buildings, said an AFP correspondent brought to the area with other journalists by Libyan authorities.
Government spokesman Ibrahim later said that the rebel National Transitional Council (NTC) had directed NATO to attack the anti-corruption agency in a bid to destroy files related to former regime officials who have joined the rebellion.
"We believe that NATO has been misled to destroy files on their corruption cases," he told journalists.
Three explosions had also been heard late yesterday in the same area.
Parts of Tripoli have been targeted almost daily by NATO-led strikes launched on March 19 after a UN resolution called for the protection of civilians from Gaddafi's regime.