As clashes mar South Sudan vote, George Clooney says “I told you so” (VIDEO)

As many as 50 people may have been killed and dozens wounded in three days of clashes in the disputed Sudan border between the north and south, according to reports.

Reports over the cause of the violence between the feuding Misseriya Arab and Ngok Dinka peoples of the oil-producing Abyei region are not clear. However, tensions there have been rising since the start of a landmark independence referendum in South Sudan on Sunday.

Hollywood star George Clooney, who visited the district on Friday, said he had repeatedly voiced his concern about the situation in Abyei and the potential for there to be a major eruption of violence there:

In Abyei "you have two tribes, the Misseriya and Ngok Dinka, inside fighting … If that sparks and one of these two troops [from the north or south] move in, breaking the CPA agreement [the 2005 peace deal], then you got yourself a north-south war," Clooney told Agence France-Presse in an interview.

Abyei had been due to hold a plebiscite on its own future on Sunday, but that was indefinitely postponed amid deadlock between northern and southern leaders over who is eligible to take part in the vote.

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.

Sudan's National Congress Party (NCP) insists that the Mesiria should be allowed to vote, while the the Dinka are backed by the Sudan People's Liberation Army (SPLA).

A senior southern leader in Sudan on Sunday blamed Khartoum for the unrest in Abyei.

"If the National Congress [Party, of the north] wants peace, cooperation and benefits with the south, the way is to cooperate with the SPLM, and to accept the implementation of the agreement on Abyei," said Deng Alor, a senior leader of the Sudan People's Liberation Movement.

U.N. peacekeepers have been sent to Abyei to investigate the violence, U.N. Mission in Sudan spokesman Kouider Zerrouk told AFP.

Western governments, in the meantime, expressed concern about the potential for bloodshed there to mar the South Sudan vote and derail its implementation of the 2005 peace deal between north and south that ended 22 years of civil war.

The United States, Britain, Norway and the United States — the three main Western brokers of the north-south peace process — highlighted their "deep concerns" about the situation in Abyei in a joint statement Sunday welcoming the first day of the southern referendum.

"We commend the people of Abyei for their patience in recent months … and we emphasise again to both parties their responsibilities to urgently resolve the impasse," the statement said.