Many more civilians surged toward the fighting waving leafy branches and demanding an end to more than a decade of turmoil.
The rebel assault — the third against Monrovia since last month — shattered hopes that a speedy deployment of international peacekeepers could avert fresh bloodshed in a country where hundreds of thousands have died in two savage civil wars.
As the battle intensified, fierce fighting broke out on the two bridges leading into downtown Monrovia and the port area.
"This is where the last fighting will take place. We will not allow them to cross the bridges," said Liberia's military chief Gen. Benjamin Yeaten by phone. The sound of heavy explosions and machine gun fire could be heard behind him.
A foreign news photographer was shot covering the fighting at one of the bridges and he was being treated at the U.S. Embassy compound. There was no immediate word on his condition.
Rebel officials, in nearby Ghana for peace talks, said they didn't intend to capture Monrovia. "We are going to let the peace process take route," said Joe Wiley of the Liberians United for Reconciliation and Democracy rebels.
Furious residents demanded to know what was keeping a long-promised peacekeeping force they hoped would be lead by Americans.
President Bush has repeatedly promised to support West African nations who plan to send 1,500 soldiers to enforce an often-violated June 17 cease-fire. But he says he is still deciding whether to send troops to the country founded in the 19th century by freed American slaves.
"If Americans want to help us, this is the time," said Varney Gbassay, as truckloads of fighters armed with AK-47s and grenade launchers raced past his house and explosions echoed in the distance. "They must not wait until everyone dies."
He said he was afraid to his leave in case his house was looted and added he had no where to run anyway.
President Charles Taylor's spokesman Vaanii Paasawe blamed a U.N. arms embargo for the country's plight. The embargo was imposed to punish Taylor's regime for trading guns for diamonds with rebels in neighboring Sierra Leone.
"They have tied our hands and feet and thrown us into a boxing ring," said Paasawe.
Taylor has not addressed the nation since the fighting crossed into Monrovia. When asked where he was, Paasawe said, "President Taylor was here" and declined to elaborate.
Long columns of people hurried toward the city center and eastern neighborhoods with rolled up mattresses, bundles of clothes and pieces of furniture balanced on their heads. Among them were pro-government militia fighters — some wearing amulets they believe will protect them in battle.
"I don't want to fight. I want peace," said Moosa Kamara, a 23-year-old in a Spider Man T-shirt who said he had been fighting with one faction or another since he was 11.
The retreat of hundreds of militia fighters reflected growing unease within Taylor's forces, many of them young men who say they fear being abandoned by the president, who agreed to resign under the June cease-fire.
In the afternoon, there was frantic looting in the city center as long unpaid pro-government fighters helped themselves to what they could find.
Meanwhile, thousands of residents streamed through the streets of a neighborhood housing diplomatic compounds seeking shelter behind their gates. The air was steamy and people, beads of sweat rolling down their brows, lugged their belongings from compound to compound, desperate for help.
The U.S. diplomatic residential compound is already crammed with some 10,000 refugees from the two recent rounds of fighting which saw rebels again fighting their way into the city.
Mary Warren, 28, a baby strapped to her back, was among those desperate for entry.
"Anywhere we go they say the place is full. I don't know what to do. Please help me," she said.
When the explosions started going off downtown her 10-year-old daughter fled their house.
She is now lost in the crowds.
The crackle of machine gunfire echoed in the background as Warren trudged on.
As some government fighters fell back from the fighting, others surged forward, piling into pickup trucks, raced in the direction of the fighting.
Later, thousands more residents came streaming back toward the fighting, chanting, "We want peace. No more war." Many were buoyed by rumors that West African peacekeeping troops had arrived in the country.
Defense Minister Daniel Chea told the crowds this wasn't true and urged them to turn back. "There is no reason for them to be on the street with mortar fire just two-and-a-half miles away," he said, a pistol on either hip.
Some protesters turned around, returning toward the city center. Others were chased away by police wielding whips and firing shots into the air.
Rebel and government officials have traded blame for instigating the latest round of hostilities, which began Wednesday. Negotiators continue to sit in Ghana working to reach agreement on a transition government that would oversee fresh elections.
Bush has repeatedly demanded that Taylor, a former warlord indicted on war crimes in neighboring Sierra Leone, resign as a first step toward peace.
Taylor has accepted an offer of sanctuary in Nigeria but only on condition that peacekeepers arrive to ensure an orderly transition.
"Everyone is talking about sending troops, but no one wants to send them," Information Minister Reginald Goodrich said. "What is the delay? They should be here."
Bush has tied any deployment of American troops to the departure of Taylor.
Taylor rose to power in 1989 and 14 years of sporadic fighting followed.
A U.N.-backed tribunal has indicted Taylor for war crimes in neighboring Sierra Leone, where he supported a brutal rebel movement infamous for hacking off people's hands, feet, ears, noses and lips.