Khartoum: At least 23 people have died in clashes with Arab nomads near Sudan`s north-south border, leaders in the contested Abyei region said on Monday, on the second day of a week-long referendum on southern independence.
Analysts cite Abyei as the most likely place for north-south tensions to erupt into violence during and after the vote, the climax of a troubled peace deal that ended decades of civil war.
The south is expected to split from the mostly Muslim north, depriving Khartoum of most of its oil reserves.
Residents of the central Abyei region were promised their own referendum on whether to join the north or the south but leaders could not agree on how to run the poll and the vote did not take place, as planned on January 09.
Leading members of Abyei`s Dinka Ngok tribe, linked with the south, accused Khartoum of arming the area`s Arab Misseriya militias in clashes on Friday, Saturday and Sunday and said they were expecting more attacks in days to come.
South Sudan`s Army said the north was also backing renegade fighters involved in recent clashes in the southern oil-producing Unity state.
US President Barack Obama on Saturday specifically warned both northern and southern leaders not to use proxy forces over the voting period, highlighting international concerns that both sides might be resorting to tactics used in past campaigns.
The northern Army`s spokesman on Sunday denied any involvement in the clashes.
A UN source, speaking on condition of anonymity, said there were reports Misseriya fighters were re-grouping in the settlement of Golih Langar on Monday, 25 km (16 miles) north of Abyei town, the headquarters of UN peacekeepers in the region and international aid groups.
"A large number of Misseriya attacked Maker village yesterday (Sunday), backed by government militia. It was the continuation of attacks on the 7th and the 8th. The first day one person died, the second day nine, yesterday 13. These are all residents of Maker," said Charles Abyei, speaker of the Abyei administration.
Southern Army spokesman Philip Aguer said fighters captured after clashes with Galwak Gai`s militia in Unity state on the eve of the vote said they had been sent from Khartoum.
"This is their last attempt to try to disrupt the voting process but they will not succeed," Aguer said.
Misseriya leader Mokhtar Babo Nimr said 13 of his men had died on Sunday`s clash and accused southerners of starting the fighting.
"They attacked us because they don`t want the Arabs to go south to water their herds but the cattle need water and they will go. If they continue to stop us going south this fighting will continue."