The BBC's Paul Welsh: The situation for the government has changed from jubilant scenes last year

Rebels who fought their way towards the centre on Wednesday said they had captured the State House government building and a number of other installations.

They were also reported to have stormed the main prison in Freetown to release their supporters, and burned down several buildings including the Nigerian embassy and the police headquarters.

Rebel leader Sam Bukari: "We are over 5,000 men"

In an interview with the BBC, rebel leader Sam Bukari said his troops numbered around 5,000 men.

Asked what it would take to stop the fighting he said he wanted to ask the Nigerian government to hand back other rebel leaders.

Gibrill Massaquoi: "Taking over reins of governments"

Earlier, Gibrill Massaquoi, a senior rebel leader telephoned the BBC to give the rebels' view of the conflict.

He said rebel armed forces and the Revolutionary United Front of Sierra Leone were in complete control of the city and taking over the reins of government."

City gains for rebels

Sierra Leone's Government and the Nigerian-led intervention force, Ecomog, have denied the rebel gains and say they are still firmly in control of Freetown.

Colonel Chris Olukolade: "Perfect security in Freetown"

Ecomog spokesman Colonel Chris Olukolade said: "I'm glad to assure the international community once more that we have achieved further successes in clearing the nuisance that the rebels tried to create."

BBC West Africa Correspondent Mark Doyle, who is in Freetown, says the claims and counter-claims are impossible to verify.

Independent reports on Wednesday said the rebels had fought their way into the city and taken up positions in the centre close to State House.

The BBC's Mark Doyle reports from the Nigerian-held international airport

Heavy fighting was also reported around the national football stadium.

Ecomog has said it still controls strategically important points in the city. Our correspondent says it is in control of the international airport, across a river estuary from Freetown city.

UN staff evacuated

As fighting intensified in the capital, the United Nations military observer mission pulled out of the country, following most of the expatriate community.

State House in Freetown: Symbol of control

The UN had been in Sierra Leone to give a mainly symbolic message of support from the international community to the government.

A spokesman for the UN's World Food Programme, Wagdi Othman, said: "The population is terrified."

Speaking from Abidjan, Ivory Coast, he said: "They don't know what is happening in the city and who is in control."

The rebels, together with remnants of the ousted military government, have made recent gains in the north of Sierra Leone.

They are loyal to the former military regime of Foday Sankoh, which ousted President Ahmad Tejan Kabbah in May 1997.

President Kabbah was restored by Ecomog forces in February 1998 and has enjoyed broad international support.