Juba, Jan 11 (Agencies): The feuding Misseriya Arab and Ngok Dinka people of the disputed Sudan district of Abyei on Monday both reported heavy losses in clashes over the past three days totalling at least 33 dead.

"Thirteen Misseriya have been killed and 38 wounded since Friday," Misseriya tribal leader Hamid al-Ansari said.

Abyei's chief administrator Deng Arop Kuol said: "The total for these three days, we lost about 20 to 22 Dinka.

"They attacked us three times already and we are expecting them to attack again today."

UN peacekeepers have been sent to Abyei to investigate, UN Mission in Sudan spokesman Kouider Zerrouk said as Western Governments expressed mounting concern about the potential for bloodshed there to derail implementation of the 2005 peace deal between north and south that ended 22 years of devastating war.

Tensions in the district on the north-south border have been rising with the launch on Sunday of a landmark independence referendum in the south.

The Misseriya, heavily armed nomads who migrate to Abyei each dry season to find water and pasture for their livestock, insist they should have the same right to vote as the Dinka, settled agriculturalists who live in the district all year and are sympathetic to the south.

Threats by the Dinka to take unilateral action over the plebiscite delay have sparked warnings of retaliation from the Misseriya.

"Security is not in place right now, because the Arabs are attacking us," said Kuol.

"We don't know whether it is the government, the militias or the Misseriya.

"The Misseriya have been seen by our people, and they're setting the stage for another attack."
South Kordofan State Governor Ahmed Haroun visited the district on Sunday to try to calm tensions, but Kuol said the visit had no impact.