Rebels in the Democratic Republic of Congo have taken control of Goma, the main city in the country's mineral-rich east, after several days of fighting with UN-backed government forces, a spokesman for the M23 rebel group has said.
Heavily armed rebels walked through the centre of the city that is home to one million people, without facing resistance on Tuesday, as United Nations peacekeepers observed and small groups of residents greeted them.
"The town of Goma fell at 11:33 local time, despite the attack helicopters, despite the heavy weapons, the FARDC [Congolese army] has let the town fall into our hands," Vianney Kazarama, an M23 spokesman, told the Reuters news agency by phone.
Al Jazeera's Nazanine Moshiri, reporting from Goma, said there had been no confrontation as the rebels entered the city.
"There are still thousands of [UN] peacekeepers here but they seem unwilling to do anything about the situation," she said, adding that the rebels were taking control of strategic positions outside the city.
"They are here for the long haul."
The rebels have reportedly taken control of the border posts between Goma and Gisenyi, a town on the Rwandan side of the border, the AFP news agency said.
'Obligation to resist'
Joseph Kabila, the country's president, urged people in Goma to "resist" the rebels' advancement.
"DR Congo is today confronted with a difficult situation," Kabila said on national television. "When a war is imposed, one has an obligation to resist. I ask that the entire population defend our sovereignty."
Earlier, Lambert Mende, a government spokesman, warned of the consequences of an M23 takeover of the city, blaming neighbouring Rwanda for backing the rebels.
"If Goma falls, it's going to create a whole other set of problems. We refuse systematically to speak to them (M23). Because if we do, it would be a way to wash away Rwanda's responsibility."
DR Congo and Rwanda have already fought two wars, the most recent of which ended in 2003 after lasting nearly six years.
On Monday, both nations accused the other of firing mortars across the narrow border which runs on one side of Goma.
The latest round of fighting erupted last week after the US and the UN imposed sanctions on the leader of the M23 rebels, Sultani Makenga.
Makenga is accused of atrocities including masterminding killings, rapes, abductions and recruiting child soldiers.
The rebels have said they plan to fight the DR Congo government "until it falls".