Another Rwanda-style crisis is looming in the northeast of the Democratic Republic of Congo, according to an international aid agency.

Christian Blind Mission (CBM), which on Friday released a grisly video of butchered victims and burning villages, said up to 5,000 people have been killed and thousands more displaced in months of tribal fighting.

"If intervention is not made immediately, we have another Rwanda situation looming, and I personally don't want to say after it has happened, 'Yes, we saw the signs, we should have done something'," the agency's regional director David McAllister told Reuters.

The agency's account is backed up by Medecins sans Frontieres (MSF) which talked last week of a "few thousand" dead and 150,000 displaced by the conflict in a rebel-held part of DR Congo. The video footage, shot on 9 January after a series of attacks on the village of Blukwa, around 50 km (30 miles) northeast of Bunia, shows a child with deep machete wounds, and a school in flames.

MSF-Holland officials said they had temporarily suspended operations in and around Bunia on Saturday because aid workers had themselves become targets in the conflict, and because they were unable to reach the neediest people.

Mr McAllister said the Lendu had been responsible for the vast majority of the attacks, and were now adding modern weapons to their traditional armoury of machetes, spears and arrows.

But he knew of at least one report of Hemas attacking a Lendu village.

Bunia, the main town in the region, is the headquarters of one of the Congo's rebel factions, a Ugandan-backed wing of the Congolese Rally for Democracy led by Ernest Wamba dia Wamba.

Mr Wamba dia Wamba told the BBC that 1,200 people had died in the violence since August, and described reports of 5,000-7,000 deaths as grossly exaggerated.

He said his group and the Ugandan army - which has a battalion in the area - were doing their best to contain the clashes.

He said the two communities had defied efforts by a commission to resolve their differences over land use and political posts.