The reports said the French embassy and cultural centre in the capital, Bissau, were also ablaze.

The President, Joao Bernardo Vieira, who had first fled to the French embassy, is now said to be in the Portuguese embassy and to have requested asylum in Portugal, the former colonial power.

Fighting between rebels and government troops erupted on Thursday, breaking a truce agreed in February.

Death toll 'around 100'

The Portuguese news agency, Lusa, said the death toll was around 100. Lusa's correspondent in the capital, Bissau, said he had seen some three dozen bodies in a city hospital.

Earlier, the news agency quoted a military source in Bissau as saying the presidential guard had surrendered on Friday morning after the rebels surrounded President Vieira's palace.

The surrender was announced in a brief statement from the president's chief of staff, Brigadier Humberto Gomes, who said he wanted to avoid further bloodshed.

"Taking account of the deteriorating situation and the interests of the country, and that enough human life has been sacrificed, the chiefs of staff of the armed forces, forces loyal to the Republic, declare their surrender," he said.

Civilians flee

There were heavy exchanges of gun and mortar fire on Thursday in several areas of the capital, as soldiers loyal to General Ansumane Mane, who began a rebellion last year, moved in on the presidential palace.

President Vieira: Whereabouts unknown

Thousands of civilians fled the city as the fighting intensified. Rebel radio urged diplomats and West African peacekeeping troops to leave Bissau.

The fighting shattered a truce agreed in February to end several months of civil war in Guinea-Bissau triggered by an army mutiny last year.

Under that agreement, a national unity government had been sworn in and Senegalese troops who had been supporting President Vieira had left the country - replaced by 600 peacekeeping troops from the West African intervention force, Ecomog.

But the rebels are reported to have been angered by the failure of Ecomog to disarm the presidential guard.

Portuguese radio said weapons from the two rival sides were stockpiled in containers earlier this year, under the supervision of a disarmament commission and the Ecomog forces.

Call for peace

Fighting between the two sides last year displaced thousands of people, depleted state finances and destroyed much of the public infrastructure in what is one of the world's 15 poorest nations.

Guinea-Bissau Prime Minister Francisco Fadul told Portuguese radio on Friday that the fighting was destroying chances for peace.