By MAGGIE FICK (AP) – 1 hour ago

AGOK, Sudan — Four months before Southern Sudan is scheduled to hold an independence referendum, tensions are already rising in this oil-rich region that sits on the expected future border, with allegations the central government is using violence and ethnic cleansing to sway the vote.

The central Sudan region of Abyei is the subject of a tug-of-war between leaders in Sudan's north and south. The border zone is home to some of Sudan's richest oil fields, worth hundreds of millions of dollars. In July 2009, an international court in The Hague ruled that the Heglig oilfields are in what would be northern Sudan. The south is appealing the decision.

In conjunction with Southern Sudan's independence referendum scheduled for Jan. 9, Abyei is to vote the same day to decide if it should belong in Sudan's north or in a possible new country in the south.

Not surprisingly, Sudan's government in Khartoum — which would only preside over northern Sudan if the independence referendum passes as expected — wants Abyei in its sphere.

Sudan's northern government may be sending Arab tribesman to settle in this Connecticut-sized patch of land in order to influence Abyei's vote, according to officials in Agok, a small town with a bustling market. Both sides argue that their people belong in Abyei, a sandy tan landscape that bursts green with lush grasses during the rainy season.

The south's Sudan Peoples' Liberation Movement says the Ngok Dinka are the traditional inhabitants, while the north's National Congress Party says the semi-nomadic Misseriah — Arabs from the north — should retain cattle grazing rights.

The top official in Abyei, Deng Arop Kuol, recently accused Khartoum of planning to resettle 75,000 ethnic Misseriah in villages where Ngok Dinka, who are southern Christians or animists, have historically lived. More Arab-leaning inhabitants of Abyei could translate into more northern-oriented votes in January.

An international official in Sudan said it is "very likely" Misseriah are settling in northern Abyei, though Kuol's numbers are probably inflated. Reports going back to last year indicated Arab settlers are moving in, said the official, who spoke on condition of anonymity because of the sensitivity of the topic between the south and north.

A Misseriah tribal chief, Mukhtar Babu Nimr, dismissed the accusations, saying there aren't even 75,000 Misseriah.

Nimr said the Ngok Dinka have held protests in Abyei in recent days, saying they don't want any Misseriah in Abyei. He said that violates the spirit of the court decision and the subsequent agreement to respect it.

"They say they don't want Misseriah in Abyei and that they will shed their blood for Abyei's sake," he said. "If they insist on that, the situation may flare up."

Nimr said there are about 30 villages in northern Abyei that are occupied by about 3,000 or 4,000 Misseriah. "Where would these people go. They (the Dinka) want to kick them out. Where to?"

Misseriah who have been in the region for 30 or 40 years should have the right to vote, said Nimr, who accused the SPLA of deploying soldiers north of Abyei in violation of agreements.

Abyei evokes emotional responses from both sides. Two years ago, northern and southern armies clashed in Abyei, causing an estimated 60,000 people to flee to safety south of a border where Sudan could split. Abyei is still being rebuilt after largely burning to the ground in the 2008 violence.

A former top Southern Sudan official said on Thursday that the south's parliament may vote to secede from Sudan if the independence referendum is delayed. John Duku, Southern Sudan's former mission chief to Kenya, said Southern Sudan can take such action under the terms of a peace deal signed in 2005 to end a north-south civil war.

If Sudan returns to civil war over the referendum, the fighting will likely start here, in Abyei.

The past several months have seen a spate of violent attacks on Ngok Dinka communities. In the latest attack, in July, at least eight people were killed in the village of Tajalei.

While the exact identity of the attackers is unknown, most people in the south point a finger northward.

"The situation in Abyei is grave," said Pagan Amum, the Secretary-General of the SPLM. "We have genuine concern that there may be a plan in action already to cause ethnic cleansing and possibly genocide in the Abyei area. The people of the Ngok Dinka are in danger of being expelled from area forcibly, with disastrous humanitarian consequences."

Sudan's peace agreement promised southerners the right to an independence vote. It also called for a referendum in Abyei to determine whether the territory would be part of the north or south, regardless of southern vote's outcome.

Preparations for both votes lag badly. One issue not yet decided is who counts as an Abyei resident. The two political parties working on such agreements haven't even appointed members of the commission tasked with carrying out the vote.

Lual Kual Lual Deng, a Ngok Dinka youth leader, said the clashes may increase during the referendum as the central government uses violence to affect Abyei's referendum or to simply seize Abyei.

Associated Press reporter Sarah El Deeb contributed to this report from Cairo.