Fighters from the M23 rebel group say they have captured Goma, the main city in resource-rich eastern Democratic Republic of Congo.

The BBC's Gabriel Gatehouse says he saw the rebels exchange some small-arms fire with the army but they otherwise met little resistance.

UN peacekeepers watched as rebels marched past their vehicles, he adds.

President Joseph Kabila, who flew to Uganda for talks, called on people to "resist" the rebels.

Aid agencies say tens of thousands of people have fled their homes in the last five days as conflict escalated.

'Defend our sovereignty'

One camp near Goma, where about 60,000 people from previous conflicts were taking refuge, has emptied as people flee, the agencies report.

This is the first time since the war officially ended in 2003 that rebels have entered Goma, raising fears that the war could resume.

Some five million people died in the war, which dragged in neighbouring states - including Rwanda, Uganda, Zimbabwe, Namibia and Angola.

M23 leader Sultani Makenga and hundreds of his fighters entered Goma, where cheering crowds shouted "welcome" and "thank you", Reuters news agency reports.

Goma has a population of about 400,000.

Our correspondents says a senior rebel commander told him that if the government refuses to enter into talks, they would carry on to Bukavu, another major city in eastern DR Congo.

In a television broadcast, Mr Kabila called on people to defend the country.

"DR Congo is today confronted with a difficult situation. When a war is imposed, one has an obligation to resist," he said, reports the AFP news agency.

"I ask that the entire population defend our sovereignty."

He later flew to Uganda to discuss the conflict with his Ugandan counterpart President Yoweri Museveni.

Rwanda has denied persistent accusations by the DR Congo government and UN that it backs the M23 rebels.

Looting

Rwandan Foreign Minister Louise Mushikiwabo said the conflict in eastern DR Congo could only be resolved through talks.

"By focussing on the blame game and ignoring the root causes of conflict in the DRC, the international community has missed the opportunity to help the DRC restore peace," she said, in comments posted on the government's website.

On Monday, Rwanda accused the Congolese army of deliberately firing across the border onto its territory.

The commander of the 22,000 United Nations peacekeepers in DR Congo, Lt-Gen Chandar Prakash, said the rebels had tried to attack his forces at the airport, but had been repelled.

Some rebels had used the cover of civilian houses to bypass the UN base there and enter the town, he said.

Our correspondent says he understands that government forces are no longer at Goma's airport, but UN forces are still there.

The UN force has not tried to resist the rebel advance, and watched as about a dozen rebels marched past their armoured vehicles, our reporter adds.

He says the rebels have gone through Goma and have reached the border with Rwanda.

"The town of Goma fell at 11:33 local time [08.33GMT], despite the attack helicopters, despite the heavy weapons, the FARDC [Congolese army] has let the town fall into our hands," M23 spokesman Colonel Vianney Kazarama told Reuters news agency.

German newspaper Tageszeitung's reporter in Goma, Simone Schlindwein, told the BBC she saw the bodies of 10 government soldiers lying in a pool of blood near the airport.

Residents told her there were many more corpses on side streets and in nearby fields.

Staff at the main hospital in Goma reported that one civilian had died and 90 had been wounded after being caught in the crossfire, Ms Schlindwein said.

Government forces had looted homes in Goma and were now retreating towards South Kivu province, she added.

Various rebels groups have been active in mineral-rich eastern DR Congo since the end of the war in 2003.

The latest conflict broke out after a mutiny in the army in April, when a group of former rebels formed the M23, also known as the Congolese Revolutionary Army.

About 500,000 people have fled the fighting since then.

The M23 is largely made up of ethnic Tutsis, the same group which dominates the government in Rwanda.

- BBC