THE Libyan government and security sources say Prime Minister Ali Zeidan has been freed by rebels, after he was abducted from his hotel.

Gunmen seized the Prime Minister from a Tripoli hotel today, and took him to a mystery location.

His absence came amid conflicting reports over whether he was formally arrested or abducted by lawless former rebels who helped topple dictator Muammar Gaddafi.

The pre-dawn seizure of Zeidan comes five days after US commandos embarrassed and angered Libya's government by capturing senior Al-Qaeda suspect Abu Anas al-Libi off the streets of Tripoli and whisking him away to a warship.

A source in the premier's office said Zeidan had been taken by gunmen from Tripoli's Corinthia Hotel, where he resides. A hotel employee confirmed a pre-dawn raid by "a large number of armed men".

media_camera Security checking vehicles outside the Corinthia hotel in the Libyan capital Tripoli after Libyan Prime Minister Ali Zeidan was kidnapped from the hotel, where he resides, at dawn by armed men and taken to an unknown location. Picture: AFP

A government statement said Zeidan had been taken "to an unknown destination for unknown reasons by a group" of men believed to be former rebels.

The Operations Cell of Libyan Revolutionaries, comprising former rebels and which had roundly denounced Libi's abduction and blamed Zeidan's government for it, said it had "arrested" Zeidan under orders of the public prosecutor.

The group, which in principle reports to the defence and interior ministries, said on Facebook it had seized Zeidan "on the prosecutor's orders".

It said he was detained for "crimes and offences prejudicial to the state" and its security.

But the cabinet said on its Facebook page that ministers were "unaware of immunity being lifted or of any arrest warrant" for the premier.

media_camera The Corinthia hotel in the Libyan capital Tripoli after Libyan Prime Minister Ali Zeidan was kidnapped from the hotel, where he resides. Picture: AFP

Later, another group of ex-rebels, the Brigade for the Fight against Crime, said it was holding Zeidan, according to the official LANA news agency.

The brigade added that Zeidan "will be well-treated", the agency reported.

Today's government statement said it suspected both the Operations Cell of Libyan Revolutionaries and the Brigade for the Fight against Crime of being behind the raid that netted Zeidan. Both groups loosely fall under the control of the defence and interior ministries but largely operate autonomously.

Zeidan is himself a former rebel who was instrumental in bringing about the downfall of Gaddafi's regime.

The career diplomat and former rebel-in-exile played a major role in securing Western support for the successful uprising. US State Department spokeswoman Jennifer Psaki, travelling with Secretary of State John Kerry in Brunei, said Thursday Washington was seeking more information on the incident.

"We are looking into these reports and we are in close touch with senior US and Libyan officials on the ground," she told reporters.

"We are working to determine more details. Our embassy staff is safe in Tripoli. We have no further details at this time."

In London, British Foreign Secretary William Hague called for Zeidan to be freed immediately.

I condemn the abduction of Libya's Prime Minister and call for his immediate release. Gov and people of #Libya have our full support — William Hague (@WilliamJHague) October 10, 2013

NATO chief Anders Fogh Rasmussen also called for his release, adding that "stability and the rule of law are very important" as Libya seeks to rebuild.

Zeidan, who was named prime minister a year ago, had on Tuesday condemned the US capture of Libi in Tripoli and insisted that all Libyans should be tried on home soil.

Libi -- real name Nazih Abdul Hamed al-Raghie -- was on the FBI's most wanted list with a $US5 million ($A5.31 million) bounty on his head for his alleged role in the 1998 twin bombings of two US embassies in East Africa.

He is reportedly being held aboard a US Navy ship in the Mediterranean.

US President Barack Obama said on Tuesday Libi was involved in plots that killed hundreds of people and would be brought to justice.

Originally published as Rebels set Libyan PM free