Seven Nepalese peacekeepers serving with the United Nations mission in Congo have been missing since Sunday, and are presumed captured by militia. The U.N. says the peacekeepers were separated from their unit during fighting with militia, during which one other Nepalese soldier was killed and three were wounded.

A U.N. spokesman says the seven Nepalese soldiers were isolated from their unit during a military operation to flush out rebels in the lawless Ituri district, where violence continues just two months before elections are due.

Kemal Saiki, the spokesman, would not give any further details, saying only that U.N. forces were looking for their colleagues.

Other U.N. and local sources, however, said the peacekeepers had been captured during the fighting north of Ituri's main town, Bunia, and were being held by a local militia leader, called Peter Karim.

Those sources, who spoke on condition of anonymity, said U.N. officials had made contact with the militiamen, who were demanding ransom.

The incident highlights the continuing violence in Congo just two months ahead of elections that are meant to draw a line under a decade of war and chaos.

Millions of Congolese are due to vote on July 30 in presidential and legislative polls that are the cornerstone of peace deals that officially ended the 1998-2003 war.

But violence continues across much of the mineral rich east, where militias and rebels continue to operate, adding to the insecurity and the death toll from Congo's war, which already stands at over four million.

Congo is home to the U.N.'s largest peacekeeping mission. But the blue helmets are stretched thinly across the vast country, and have to operate in difficult conditions.