As gunfire crackled, the Tutsi rebels said they had reached the outskirts of Goma and declared a unilateral cease-fire to prevent panic as the army retreats and residents flee.
Congo said Rwandan troops had crossed the border and attacked its soldiers - raising the specter that neighboring nations will again be drawn into Congo's war. Rwanda's Tutsi-led government immediately denied the charge, but Congo turned to Angola for help defending its territory.
As the chaos mounted, the US announced its officials were leaving Goma and urged all American citizens to do the same. The State Department said Assistant Secretary of State for African Affairs Jendayi Frazer was heading to the capital, Kinshasa, and would arrive tomorrow.
"There is a lot of violence," said spokesman Sean McCormack. "This is of deep concern to us."
Thousands of panicked refugees clogged the dirt roads out of Goma, struggling to reach safety.
Women carrying huge bundles on their heads and babies in their arms trudged alongside men pushing crude wooden carts crammed with clothing, food and cooking utensils. Bewildered children walked alongside. Young boys led goats and pigs on tethers as men on bicycles weaved in and out.
The U.N. High Commissioner for Refugees said about 45,000 people fled the nearby village of Kibati, where they had been sleeping in a makeshift camp in the open air, in a matter of hours on Wednesday.
"It was very chaotic," said agency spokesman Ron Redmond, speaking from Geneva. Most of the refugees had arrived only the day before after fleeing fighting farther north.
"They suddenly became very agitated and people began leaving the camp in a panic," Redmond said. They first headed toward Goma to the south, then changed direction and headed back out as it became clear the city was about to fall.
Goma's governor, Julien Mpaluku, acknowledged that panic was spreading, but stressed that U.N. peacekeepers were still in charge and rebels had not yet entered the city. U.N. spokesman Madnodje Mounoubai said peacekeepers were deployed at the airport and at other strategic points.
A rebel statement said their fighters were just outside Goma.
"We are not far from Goma," rebel leader Laurent Nkunda was quoted as saying on the BBC's Web site. "But because there is a state of destabilization in the town we decided ... unilaterally to proclaim a cease-fire."
Nkunda, who has ignored calls by the Security Council to respect a U.N.-brokered truce signed in January, called on government forces to follow suit.
The U.N. says its biggest peacekeeping mission - a 17,000-strong force - is now stretched to the limit with the surge in fighting and needs more troops quickly. India, Pakistan, Bangladesh, Uruguay and South Africa are the main contributors to the existing force.
But hopes for immediate backup from the European Union dimmed. French Foreign Minister Bernard Kouchner said Wednesday the EU had considered sending troops to reinforce the peacekeepers in Congo but some countries refused.
Fears have grown of a wider war that could drag in Congo's neighbors. Congo suffered back-to-back wars from 1996 to 2002 that embroiled eight African nations and became a rush at the country's vast mineral wealth.
The unrest in eastern Congo has been fueled by festering hatreds left over from the 1994 Rwandan genocide, in which half a million Tutsis were slaughtered. More than a million Hutu extremists fled to Congo where they regrouped in a brutal militia that helps fuel the continuing conflict in Congo.
Rebel leader Nkunda, an ethnic Tutsi and former general, quit the army several years ago, claiming the government of President Joseph Kabila was not doing enough to protect minority Tutsis from the Hutu extremists.
On Wednesday, retreating government soldiers entered Goma along with the fleeing refugees, grabbing cars, taxis and motorbikes to help in their escape.
About 15 soldiers briefly commandeered a car carrying an AP cameraman and photographer and demanded to be driven about 50 miles to the town of Saki.
"I'll kill you! I'll kill you!" yelled one soldier in front of an airfield near downtown Goma.
The soldiers grabbed boxes that looked like ammunition from the U.N. compound at the airport, piled them into the SUV and took off. Some of the soldiers piled onto the roof, others hung from open doors. The journalists finally managed to get away, jumping out of the moving vehicle at a military police checkpoint.
On another battlefront further north, government soldiers abandoned the town of Rutshuru and tens of thousands or refugees fled, according to U.N. officials and aid workers.
"It's incredibly dangerous," said Alice Gilbert, a project officer for the British medical agency Merlin. "Complete chaos broke out and everyone fled into the bush."
