"I declare the beginning and assumption of the executive committee's work in Tripoli," Ali Tarhuni, a senior official of the rebel National Transitional Council, told a press conference in the capital.
"Long live democratic and constitutional Libya and glory to our martyrs," he said, announcing the holders of key posts in a new provisional government.
Tarhuni, the executive committee's vice-chairman and minister of oil and economics, said NTC head Mustafa Abdel Jalil would arrive in Tripoli as soon as the security situation permitted.
He called on forces loyal to Muammar Gaddafi to lay down their arms promising their safety and lawful treatment.
"Put your weapons down and go home. We will not take revenge. Between us and between you is the law. I promise you will be safe." At the same time the UN Security Council released USD 1.5 billion of seized Libyan assets to be used for emergency aid after the US and South Africa ended a dispute over the money.
The assets were frozen in US banks, but South Africa had blocked the release on the UN Security Council's sanctions committee, saying it would imply recognition of the NTC. The last-minute accord with South Africa meant that the US did not press for a Security Council vote. A new request was immediately made and approved by the Libya sanctions committee, diplomats said.
"The money will be moving within days," a US diplomat said.