The United Nations says it is investigating claims that more than 2,000 people have been killed in tribal clashes in the north-east of the Democratic Republic of Congo.

The commander of the UN mission in the country, General Mountaga Diallo, said he was trying to send a team to Ituri province, where the Hema - a minority tribe in the area - say many of their people were killed by the majority Lendu.

People are complaining that we haven't been doing more, but we are here with only the mandate provided within the Lusaka peace agreement on Congo

General Diallo UN Congo mission

But he added that efforts to verify these claims were hampered by a lack of security guarantees in the region.

"It appears the situation is worsening, and I am afraid we are yet to see the worst," he said.

Thousands of people have been killed in recent years in fighting between the Lendu and Hema over land and natural resources.

Fresh clashes

Hema representatives asked the UN to investigate at least 2,400 deaths which they say resulted from more than 70 attacks since April, and to demilitarise the area.

The long-standing rivalry between the Hemas and Lendus has been exacerbated by the war in DR Congo, with each side backing rival warlords.

General Diallo said the rebels and the Ugandan army, who control the area, had refused to provide an escort for his team to travel to the villages north of the town of Bunia, on the border with Uganda, where the massacres are reported to have taken place.

But he added that he would himself fly to Kampala later this week to discuss ways of calming the situation with the Ugandan authorities.

He stressed that the UN mission was in Congo as an observer mission only, and that its mandate did not stretch to intervention in local factional fighting.

Old enmities

"People are complaining that we haven't been doing more, but we are here with only the mandate provided for within the Lusaka peace agreement on Congo," he said.

There have been sporadic, but very bloody outbreaks of violence between the Hema and the Lendu in the region for the past three years.

The traditionally pastoralist Hema outnumber the Lendu, who rely on growing crops, by about five to one.

The two communities have clashed for decades over tea and coffee farms, as well as cattle, which form the backbone of the local economy.

General Diallo said the groups had organised into militias, set up training camps and acquired automatic weapons to intensify their conflict.

Uganda has been accused in the past of pitting the two communities against each other, allegations it has denied.