Thousands of people have been forced to flee the capital. Taylor says he will go only when a peace mission will be in the country. USA is considering sending limiting peacekeeping forces but only after Taylor quits.

President Charles Taylor vowed to fight to the last man against rebels thrusting into the Liberian capital in a fierce assault that forced tens of thousands of residents to flee.

Taylor accused the United States of having ?blood on its hands? for urging him to step down, which he said had undermined his ability to mount a defence against rebels lobbing mortar bombs into the capital.

?We must fight and we will continue to resist to the very last man until these murderers stop killing you, our people,? Taylor told his own Kiss FM radio station. ?I say to the United States, this blood is also on your hands because you have prevented me, the president, from providing adequate assistance and adequate protection for my people.?

The former warlord was speaking after thousands of people scrambled for cover from zipping bullets and flying shrapnel that ruined hopes West African peacekeepers would arrive quickly to prevent a bloodbath and let Taylor leave step down.

The United States, under pressure to intervene to stop the bloodshed in a country founded by freed American slaves in the 19th century, has said it is considering sending limiting peacekeeping forces but only after Taylor quits. Taylor reiterated that he would only go when peacekeepers are already in place.

Rebels streamed across a river bridge they had earlier wrested from loyalist troops, taking positions a few kilometres from the city centre, which they hammered with volleys of mortar rounds, killing at least one person, witnesses said. Taylor?s forces said they had pushed back the rebels after they passed Monrovia?s port area and neared another bridge at the entrance to the city centre.

?We are still fighting here,? Taylor?s chief of army staff General Benjamin Yeaten told Reuters from the Vai Town area beyond a bridge into the heart of the city. The sound of rapid gunfire and heavy explosions could be heard in the background.

Defence Minister, Daniel Chea, said 20 civilians had been killed in the fighting, although there was no way to confirm that. Diplomats said a French photographer was wounded during the fighting in the coastal city and was in a serious condition. He received treatment at the United States embassy and was due to be evacuated. No more details were available.

Many of Taylor?s troops said they did not want to risk their lives for the president ? who is wanted for war crimes by a UN-backed court in Sierra Leone and hemmed in by Rebels of the Liberians United for Reconciliation and Democracy (LURD) and another rebel group, Model. Nigeria has offered him asylum.

?What are we fighting for?

?What are we fighting for? The man we are trying to defend has decided to go. So why should we fight to die?? said one, Commander Klon, near the port area. Two previous rebel attacks killed hundreds last month. West Africa?s military powerhouse Nigeria said a military team was heading to Liberia to assess the terrain in readiness for deploying a larger intervention force.

LURD launched the attack after seizing the key Po River bridge, 12 km from Monrovia?s outskirts, on Friday. Aid agencies estimate that up to 200,000 people uprooted by fighting were already squatting in camps in Monrovia.

?And now it?s going to be even worse,? said Magnus Wolfe-Murray of British medical agency Merlin. ?Every time the fighting comes there?s another 10, 20, 30, 40 thousand people.?

Demonstrations sprung up around the city. People waving leaves as a symbol of peace chanted : ?we told you to go to school, but you are still holding guns? at the fighters. Police fired in the air to clear thousands of people who demonstrated after a false rumour that African peacekeepers had arrived.

A small crowd also begged the US embassy for help. Taylor?s government and rebels signed a ceasefire on June 17 at talks in Ghana, but the truce has repeatedly been violated.

Matthew Tostevin