Tripoli. Libyan Prime Minister Ali Zidan has been freed hours after he was seized by former rebels, a spokesman of the foreign ministry said."He has been freed but we have no details so far on the circumstances of his release,” Mohammed Abdelaziz told AFP news agency. Government spokesman Mohammed Kaabar told the agency, LANA, that Zeidan was "set free” and was on his way to his office on Thursday.The brief report gave no further information. Details were sketchy but it appeared Libyan forces had intervened in some way and that the abductors did not free Zeidan voluntarily.The pre-dawn seizure of Zeidan came five days after US commandos embarrassed and angered Libya’s government by the capture of a senior al-Qaeda suspect, Abu Anas al-Libi, off the streets of Tripoli. A former Libyan rebel group said on Thursday it had "arrested” Zeidan after the government allowed the United States to capture al-Liby.The Libyan Revolutionary Operations Chamber said on Facebook it had seized the prime minister "on the prosecutor’s orders,” adding that Zeidan "was arrested under the Libyan penal code... on the instructions of the public prosecutor”.But the cabinet said on its Facebook page that ministers were "unaware of immunity being lifted or of any arrest warrant” for the prime minister.Thursday’s government statement said it suspected both the Revolutionary Operations Chamber 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.Two years after the revolution that toppled Gaddafi, Libya’s new authorities are struggling to rein in tribal groups and groups of former rebels.Speaking to Al Jazeera from London, Middle East analyst Abdel Bari Atwan, said the incident confirmed that "Libya is a failed state”."The rebels have the upper hand and the army cannot intervene. It is chaos. This is a huge embarrassment for the government,” Atwan said.