Three Pygmies were mutilated and killed by separatist militiamen in the Katanga province of Democratic Republic of Congo, further stoking inter-ethnic tensions, the UN said on Wednesday.

Fighters from the Bakata Katanga group burned several houses in the Kasinge area in the north of the province last week, before "attacking civilian Pygmies", Lieutenant Colonel Felix Prosper Basse, of the UN mission in the country, said.

"Three Pygmies were mutilated before being killed by the militiamen," who came from the Baluba ethnic group, he said.

In May 2013 Bakata Katanga rebels launched bloody attacks on Pygmy areas, provoking clashes between the two communities which have worried humanitarian workers.

The US group Refugees International last week appealed for more UN peacekeepers in the region to protect civilians "more efficiently".

The commander of the UN mission, General Carlos Alberto dos Santos Cruz, told a press conference on Wednesday that "political work was also needed to stop the violence in Katanga".

The country's interior minister Richard Muyej took part in meetings in the mineral-rich southern region on Tuesday, which broke away from Kinshasa for three years in the early 1960s, to discuss inter-ethnic tensions.

"We have to work to lower tensions... and to lay the basis for reconciliation," he told national television.

Pygmies are a hunter-gatherer people who are found in the DRC, Central Africa, Congo, Cameroon and Gabon. Their way of life is threatened by deforestation, mining and increasing pressure on agricultural land.

They face discrimination and contempt from other ethnic groups in the area, who often exploit them, paying them in cigarettes or alcohol.

Hundreds of Pygmies marched through the streets of the capital Kinshasa on Saturday to denounce "massacres" in Katanga, and to plead for peaceful cohabitation between the communities.

Last month they petitioned the parliament for a law on Pygmy rights.