RAF jets bomb Tripoli control centre

The alliance said the dictator was not a target and there was no way of knowing whether he was there at the time of the raid.

RAF Typhoons were among the aircraft that used precision guided weapons in Libya to bring down guard towers along the walls of the Bab Al Aziziyah complex in the centre of Tripoli in the early hours.

The Chief of Defence Staff's spokesman, Major General John Lorimer, said: "For decades, Colonel Gaddafi has hidden from the Libyan people behind these walls, spreading terror and crushing opposition.

"The massive compound has not just been his home but is also a major military barracks and headquarters and lies at the heart of his network of secret police and intelligence agencies.

"Last night's action sends a powerful message to the regime's leadership and to those involved in delivering Colonel Gaddafi's attacks on civilians that they are no longer hidden away from the Libyan people behind high walls."

Previous Nato attacks have hit command and control and other military facilities within the complex, he added.

The compound was badly damaged by US warplanes 25 years ago in response to a bombing that had killed two US servicemen at a German disco.

Saturday's air strike came as Nato prepared to deploy attack helicopters over Libya for the first time.

With the international community trying to intensify pressure on Gaddafi to relinquish power, Prime Minister David Cameron has confirmed that British Apache helicopters will join the latest offensive.

This comes amid intelligence reports that the dictator's behaviour is becoming increasingly erratic.

And the Libyan regime was looking completely isolated on the world stage after Russia joined Western calls for Gaddafi to step down.

But there are concerns that the deployment of Apaches represents a further escalation of the conflict that could breach the terms of United Nations Security Council resolution 1973.

John Baron, the only Conservative MP to oppose intervention in Libya in a parliamentary vote in March, warned that Britain was "getting down further and further into this conflict".

Mr Cameron said on Friday he had thought "very carefully" before taking the decision to deploy the helicopters for closer-quarters combat.

"As soon as you make that decision you have to be prepared as Prime Minister of our country to bear that risk," he said.

"I think very carefully before all the decisions we take. I clearly thought very carefully before we took part in any operations."

Mr Cameron added: "Three months into the operation I believe we are entering a new phase.

"It is right that we are ratcheting up the military, the economic and the political pressure on the Gaddafi regime so that we can enforce resolution 1973."

Russia, which has previously criticised the Nato air strikes in Libya, signed up to a G8 communique on Friday calling for Gaddafi to step down and offered to mediate his departure.