US President Barack Obama had made a secret deal with Libyan rebel leaders to capture the freed Lockerbie bomber from Libya and return him to face justice in the US, the Mail on Sunday reported yesterday.

The British daily quoted senior congressional sources in Washington as saying that Mr Obama had told the Libyan rebels through intermediaries that a condition of Washington’s continued support was that they must hand over Abdelbaset al-Megrahi to US special forces if they enter Tripoli.

The mission would involve Megrahi being flown to a neutral Arab country by US special forces and on to the US to face trial. Megrahi, 59, a former Libyan intelligence officer, was convicted in 2001 and sentenced to life imprisonment for the 1988 bombing of Pan Am Flight 103 over Lockerbie, which killed 270 people.

He was freed on compassionate grounds by the Scottish government in August 2009 and flown to Libya after doctors said he had terminal prostate cancer and had three months to live.

The report came as NATO said it had begun ramping up its airstrikes on military targets in the western part of Libya, where rebel forces claim a string of advances through territory still largely under Muammar Gaddafi’s control.

On Saturday, Gaddafi warned Europe of stinging attacks unless NATO halted its air war, drawing a strong rebuke from US Secretary of State Hillary Clinton.

“Instead of issuing threats, Gaddafi should put the wellbeing and interests of his own people first and he should step down from power and help facilitate a democratic transition,” Mrs Clinton said on a visit to NATO ally Spain, the latest leg of an European tour.

In a speech broadcast by loudspeaker to thousands of supporters in Tripoli’s Green Square on Friday, Gaddafi had warned that his loyalists could attack Europe like “locusts and bees”.

“The Libyan people are capable, one day, of taking the battle to Europe and the Mediterranean,” he said.

In a boost for Gaddafi, the African Union yesterday called on member states to disregard an arrest warrant issued by the International Criminal Court for the Libyan leader. That could allow Gaddafi to travel freely on the continent. The warrant was issued for his alleged role in a crackdown on anti-government protesters earlier this year.

Libyan government spokesman Moussa Ibrahim praised the AU’s decision, saying “we salute their courage”. He said Gaddafi had no immediate plans to leave the country.