According to our source, Libyan Prime Minister Ali Zeidan has called on Western powers to help stop the spread of militancy in his country.

In an interview with BBC Newsnight, he said Libya was being used as a base to export weapons throughout the region.

"The movement of these weapons endangers neighbouring countries too, so there must be international co-operation to stop it," Mr Zeidan said.

On Monday Libya questioned the US ambassador over the capture of a suspected al-Qaeda leader in Tripoli.

Anas al-Liby, wanted over the 1998 bombings of US embassies in Kenya and Tanzania, was seized by US commandos in an early morning raid on Saturday.

The US has defended the capture saying that Mr Liby - whose real name is Nazih Abdul-Hamed al-Ruqai - was "a legal and an appropriate target".

But Libya's national congress on Tuesday demanded his return, calling his capture a kidnapping that amounted to a "flagrant violation of the country's national sovereignty".

President Barack Obama told reporters on Tuesday that the US had strong evidence that he had "planned and helped execute plots that killed hundreds of people - a whole lot of Americans". "He will be brought to justice," he said.

Mr Liby is believed to have been one of the masterminds behind the 1998 US embassy attacks, which killed more than 220 people in Kenya and Tanzania.

The 49-year-old has been indicted in a New York court in connection with the attacks and has been on the FBI's most wanted list for more than a decade with a $5m (£3.1m) bounty on his head.