KHARTOUM // Even as southern Sudan celebrates its historic independence referendum, many people are becoming increasingly worried about the rangy young men with machine guns in the disputed border region of Abyei.
Abyei, a vast area of grassland and swamp dotted with villages of distinctive mud-thatched huts, straddles the country's badly defined border and is claimed by both the north and south.
It symbolises the issues that have ravaged Sudan for years: ethnic intolerance, obscure boundaries, oil reserves, and blood feuds.
Three days of deadly firefights earlier this month, between the Ngok Dinka and Misseriya tribesmen, resulted in reports of anywhere from several dozen deaths to as many as 100 people killed.
Once again, the region is the country's powder keg.
"War is very likely," said Arob Deng, an Abyei native who works for the Kenana Sugar Company in Khartoum.
There is no question, he says, that the vast territory belongs to his tribe, which lives in the area year round.
His attitude is typical of members of the Ngok Dinka, African cattle herders affiliated with the southern tribes who would want to join a newly independent south.
"The problem is, if you have an area which through history is clearly southern, and there is a dispute, there could be serious repercussions," warns Mr Deng, whose father was chief of the tribe until the late 1960s.
The Misseriya, the larger of the two tribes, outnumber the Ngok Dinka by five to one, Mr Deng said, "so, if they were allowed to vote, we know what would happen."
The Misseriya are Arab nomads who migrate to Abyei for several months every year during the brutal dry season so their thin cattle can graze on the grasses near a river known in the south as the Kiir and Bahr el Arab in the north.
During the country's 20-year civil war which claimed two million lives, the Ngok Dinka backed the south's Sudan People's Liberation Army (SPLA), while Misseriya militiamen fought as proxies for the government in Khartoum. Burned-out buildings still dot the landscape.
If the tribes do go to war, some fear that rekindled animosities could imperil the 2005 peace agreement that led to this month's internationally backed referendum to decide whether the Christian and animist African tribes of the south will break away from the Muslim Arab tribes of the north.
The votes in the referendum are to be counted over the next two weeks. It is widely expected to lead to the creation of the world's newest independent nation in the south in July.
Abyei, whose status was disputed during the US-brokered peace talks, was supposed to decide its north-south affiliation in its own referendum on January 9, coinciding with the week-long one that took place in southern Sudan. It never went forward because no one was able to agree on who is a resident of Abyei - and thus eligible to cast a ballot.
There are wildly varying accounts of how the recent clashes broke out.
One Misseriya leader, Sadig Babo Nimir, said his tribesmen were attacked without provocation on January 7, two days before the start of polling in the referendum.
"While young boys were grazing [their cattle], the SPLA fired shots at their cattle," he said.
He claims that the following day "15 rocket missiles were fired, injuring five of the Misseriya".
And on January 9, he claims, "the Misseriya were forced to retaliate and attacked an SPLA garrison killing 100 members", adding that his people had seized hundreds of weapons from the Ngok Dinka.
Col Philip Aguer Tamyang, a spokesman for the SPLA, which is supported by the Ngok Dinka, claims that the Misseriya militia known as the Popular Defence Force attacked first.
Abyei police and armed young men of the Ngok Dinka had no choice but to mount a counter-offensive, he says.
He denies Misseriya accusations that the SPLA started the conflict: "The SPLA did not attack the Misseriya. There is a UN Peacekeeping force and a monitoring team that carries out surveillance in the area so they can vouch for this."
The situation in Abyei has calmed somewhat after two rounds of emergency talks between the tribes, which agreed that if any more people from one tribe died that the other would have to pay compensation. However, Abyei is still filled with armed young men from the militias belonging to both tribes, who are reportedly carrying assault rifles, rocket-propelled grenades and machetes.
In 2008, similar clashes that broke after a power-sharing arrangement fell apart killed 200 people.
Representatives from the north and south are now scheduled to hold a series of meetings over the next six months to determine the fate of Abyei.
The SPLA will continue to press for an Abyei referendum, said Col Tamyang.
However, southerners believe the north, smarting from the south's apparently overwhelming vote in favour of independence, may be digging in its heels over Abyei.
"The problem goes beyond the Misseriya because within both communities there is no problem, it can be resolved in peaceful dialogue. However, the Misseriya are hostages of the political elite of the north," said Col Tamyang.
He claimed that the north continues to provide arms to the Arab herders.
Meanwhile, the citizens of Abyei fret about what will happen next, and hope that the international community will not ignore the region now that voting in the main referendum has concluded with little violence.
"It is something very unfortunate that the people of Abyei have been denied the right to vote. It is very important for us to know what the future holds for the sake of the next generation, otherwise we will see further violence," said Maw Adol, a member of the Ngok Dinka who works in the finance ministry of South Sudan.