Rebels in Liberia, defying the ceasefire in the civil war reached last week, have launched a fresh assault on the capital Monrovia.
Both sides accuse the other of breaking the ceasefire
The attack is the latest in a series of violations reported by both government and rebels since the two sides signed a peace agreement.
Pandemonium broke out in Monrovia as the rebel move began, reports the BBC's correspondent in the city, Jonathan Paye-Layleh.
The rebels advanced from the town of Klay, firing on
government troops on the strategic Po River bridge
12 kilometres outside Monrovia.
Pro-government fighters moved out of the city at speed to try to repulse them.
We will continue to run and run - there's no end to our running
Our correspondent says people ran amok in central Monrovia and traders abandoned their stalls to run for their lives.
Residents again streamed towards the middle of town from the direction of Duala, which was heavily contested when the rebels entered the capital for the first time earlier this month.
"We will continue to run and run, there's no end to our running," said a middle-aged women rushing to catch a taxi.
Residents in the Virginia and Brewerville townships
said on the telephone they could hear heavy explosions.
Elsewhere, heavily-armed government forces have been patrolling the north-eastern town of Ganta, after forcing out fighters from the Liberians United for Reconciliation and Democracy (Lurd) rebel group.
The rebels have used heavy fire power to try to recapture the once commercially lively city.
Our correspondent says retreating rebels set on fire almost every building in the town as they left.
And senior battlefront commander General Benjamin Yeten, talking to reporters, described rebel actions as "wicked and painful".
Lurd says it is boycotting peace talks, accusing the chief mediator of allowing President Charles Taylor to renege on a commitment to step down.
The group demanded that mediator Mohamed Ibn Chambas leave the talks, calling him a "spokesman" for President Taylor.
An agreement reached at the talks last week gave the rebels and the government 30 days to establish an interim authority that excluded President Taylor.
The other rebel group - the Movement for Democracy in Liberia - has backed the demands for Mr Taylor to go, throwing the peace effort into further confusion.
Mr Chambas is executive secretary of the Economic Community of West African States (Ecowas), which has been trying desperately to find a solution to the Liberian conflict.
Indicted on war crimes charges
Under UN sanctions
Won 1997 elections
He did not say whether he would withdraw and urged all parties to stick with the peace process.
"It is for all of us, our duty to co-operate with each other in the true spirit of the negotiations," he told the Associated Press news agency.
"I urge them to return to the peace talks because the only option is to stay."
President Taylor said last week that he did not intend to step down before his term ends next year and may seek re-election.
Elsewhere, the Swiss authorities have agreed to block bank accounts belonging to Charles Taylor.
This follows a request from the United Nations-backed war crimes court in Sierra Leone.
The UN-backed Special Court for Sierra Leone has indicted Mr Taylor for alleged war crimes during the brutal war, which ended last year.