Libya's state news agency says Prime Minister Ali Zeidan has been freed, several hours after he was seized by a group of former rebels.
There were no immediate details on the circumstances of Zeidan's release.
Earlier on October 10, a former rebel militia said it had "arrested" Zeidan for his government's involvement in the capture of a top Al-Qaeda suspect by U.S. forces in the Libyan capital on October 5.
It said Zeidan was arrested on "prosecutor's orders," but the government denied any knowledge of an arrest warrant for the prime minister.
It denounced his seizure as a "criminal act" and said it will not give in to "blackmail."
Libyan authorities are struggling to contain rival armed groups, two years after the uprising that overthrew longtime ruler Muammar Qaddafi.
Based on reporting by AFP, dpa, and Reuters