African leaders have called for an immediate ceasefire in eastern Democratic Republic of Congo (DRC), as heavy fighting between government forces and a Tutsi militia continued in the country's North Kivu province.

Regional leaders demanded an end to the clashes and the establishment of a "humanitarian corridor" to aid the thousands of refugees displaced by the fighting.

"There should be an immediate ceasefire by all the armed men and militia in North Kivu," said Moses Wetangula, Kenya's foreign minister, reading a communique agreed by seven African leaders at their meeting in Nairobi, Kenya's capital, on Friday.

He said that regional peacekeepers could be sent to North Kivu if required.

But there are fears that regional forces could be drawn into the conflict and Ban Ki-moon, the UN secretary-general, warned delegates at the Kenya summit that the conflict could grow to engulf the region.

"It is only at the political level, here in your region, that lasting solutions can be found. There can be no military solution to this crisis," he said.

Regional divisions

Angolan troops have already joined Congolese soldiers battling the Tutsi fighters near the city of Goma, UN officials reported on Friday.

The Tutsi fighters are loyal to Laurent Nkunda, a renegade Congoloese army general who says he is fighting to protect ethnic Tutsis and liberate all of Congo from a corrupt government.

The DRC's government says that Nkunda is backed by Rwanda's Tutsi administration.

Nkunda was not invited to the talks in Nairobi, the Kenyan capital.

"He is a key player and he's not here today," said Al Jazeera's Zeina Awad, reporting from the conference. "That pretty much puts a limit on what can come out today."

"[But] they have told us they've put forward a 'mechanism' ... that will shuttle between all the parties, including Laurent Nkunda," she said.

"He was not at the table today, but talking to him has not been ruled out."

Soon after the talks closed, an unnamed spokesman for Nkunda was quoted by the AFP news agency as saying the summit had turned out to be "for nothing".

Renewed clashes

During the talks, clashes continued between Nkunda's fighters and Congolese government forces close to the Kibati refugee camp, where there are about 45,000 refugees from the fighting elsewhere in North Kivu province.

"And this fighting is taking place less than 7km from Goma."

The UN's refugee agency said that the shooting lasted for about 30 minutes, causing panic among the refugee population and interrupting aid distribution.

The road south towards Goma was again lined with refugees fleeing the conflict, as it had been last week.

The UN estimates that about 253,000 people have been displaced since September.

Civilians killed

Several international aid and rights agencies say that civilians are being deliberately targeted.

The groups, including Human Rights Watch, said in a statement: "At least 100 civilians have been killed and more than 200 wounded since combat resumed in late August 2008 between the forces of the rebel commander Laurent Nkunda and Congolese army soldiers.

"Many of those killed were trapped in combat zones, unable to flee, while others were deliberately killed by combatants."

An official from Monuc, the UN mission to the DRC, said that an investigation into human rights violations was under way.

"A Monuc team comprising members of the human rights section has left by helicopter for Kiwanja," which was the scene of heavy fighting on Tuesday and Wednesday, Matlodje Mounoubai, a Monuc spokesman said.

Monuc is the UN's largest peacekeeping force with 17,000 troops, but it has only a few hundred in the areas affected by the latest violence and has been unable to curb the fighting and displacement.