Libyan PM Ali Zeidan has called for “rationality and wisdom” after being freed from the custody of militiamen.
He was abducted from a Tripoli hotel and held for several hours by armed men whose identity has yet to be confirmed.
In a cabinet meeting, the PM thanked “real revolutionaries” who took part in a security operation to free him.
The motive of the abduction is unclear but some militias had been angered by a US commando raid to capture senior al-Qaeda suspect Anas al-Liby.
Many militia groups saw the raid in Tripoli on Saturday as a breach of Libyan sovereignty and there is growing pressure on the government to explain if it was involved.
One group, the Libya Revolutionaries Operations Room (LROR), said it had captured Mr Zeidan, claiming it was acting on orders from the prosecutor general. But the justice ministry denied this.
The LROR said its actions had not been related to Mr Liby’s detention.
The official Lana news agency also named another formal rebel group, the Brigade for the Fight against Crime, as being involved.
Two years after the overthrow of Col Muammar Gaddafi, Libya still has no constitution and divisions between secular and Islamist forces have paralysed parliament.
The government has been struggling to contain the numerous militias who control many parts of the country.
Mr Zeidan’s cabinet meeting following his release was shown live on Libya’s al-Ahrar television.
He thanked those who had helped free him but gave no details about them or the abductors.
He said: “I salute the revolutionaries who had an important role. The real revolutionaries, those who rose above greedy demands, I salute them for what they did in this affair.”
Mr Zeidan urged them to “assimilate into the state, and play an active role in it through its civilian and military institutions”.
He added: “Only with an army and the police can a state exist.”
The BBC has been told that local armed residents backed by brigades from nearby districts had rescued the PM, our correspondent in Tripoli, Rana Jawad, says.
The prime minister said of his capture: “These are accidental things from the revolution’s overflow and they will disappear.”
He also said Libya would “regain its health” and be “an active, positive nation”.
Mr Zeidan assured foreigners the incident had happened “within the context of Libyan political wrangles”.
He ended by calling for “caution and rationality in handling this matter”.
A spokesperson for David Cameron said the UK Prime Minister had spoken to Mr Zeidan since his release and had promised to help build a “stable, free, peaceful and prosperous” Libya.
The spokesperson said: “Both leaders agreed that Libya’s democratically elected representatives and leaders must be able to carry out their duties and deliver Libya’s political transition free from the threat of kidnap, violence and armed intimidation. A minority of individuals must not be allowed to undermine that.”
Mr Zeidan had been taken in a pre-dawn raid on the Corinthia Hotel by more than 100 armed men.
Photographs circulating online showed Mr Zeidan being surrounded and led away. There were no reports of violence during his capture.
The prime minister was reportedly held at the interior ministry anti-crime department in Tripoli, where an official said he was treated well.
In a news conference shortly before the release was announced, the government condemned the “criminal act” of his detention and said it would not give in to “blackmail”.
The LROR is one of a number of militias operating in Libya which are nominally attached to government ministries but often act independently and, correspondents say, often have the upper hand over police and army forces.
Earlier this week, the prime minister appealed for Western help in tackling rising militancy in Libya.
In an interview with the BBC on Monday, he said Libya was being used as a base to export weapons throughout the region.
Mr Liby, 49, 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.
He was living openly in Tripoli before his capture by US commandos early on Saturday morning.
In remains unclear whether the Libyan government had prior knowledge of the operation to capture him.