A disputed region in Sudan could turn into another conflict to rival that in Darfur, a think-tank has warned.
The International Crisis Group said the main political parties and the international community needed to deal with the crisis before polls in 2009.
"South Kordofan is a Sudan in miniature, with heavily armed African and Arab tribes living side by side," ICG's Fouad Hikmat told the BBC.
The state was bitterly contested during the north-south war that ended in 2005.
A peace agreement between the Sudanese government and the southern rebel movement ended one of Africa's longest and bloodiest conflicts, with the two parties supposed to share power and the country's oil wealth.
But the situation in Southern Kordofan, which lies to the north of the border of South Sudan and borders Darfur, could be the domino that tips over the peace in the south, and possibly, the entire country, the ICG says.
In a report entitled Sudanís Southern Kordofan: The Next Darfur? it says the main northern and southern political parties - President Omar al-Bashir's NCP and the ex-rebel SPLM - have been "dangerously engaged in ethnic polarisation" in advance of elections.
There were violent clashes between northern and southern groups earlier this year in the oil-rich Abyei region, which was incorporated into Southern Kordofan under the 2005 peace deal.
The disputed Nuba Mountains area was also brought into the enlarged Southern Kordofan State.
Last week's kidnapping of nine Chinese oil workers in the state is an illustration of the volatility of the situation, it says.
"There is frustration everywhere, there is frustration among the Arabs, there is frustration among the Nuba tribes and with all this frustration, there is no adequate responses to it - they can all converge and [be] expressed through violence,'' Mr Hikmat told the BBC.
More than two million Darfuris are believed to have fled their villages
The conflict in Darfur began more than five years ago after a rebel group began attacking government targets, saying the region was being neglected and accusing Khartoum of oppressing black Africans in favour of Arabs.
The think-tank says reconciliation between Southern Kordofan's ethnic groups was paramount as people there were well armed, but felt let down by the failure of "peace dividends".
According to the report, developmental projects in the state have stalled, as has political integration and hundreds of people have died in land disputes over grazing rights.
There is still time to calm the situation before the elections, if action is taken now, the ICG says.
Although the NCP and the SPLM work together in the national government, many former rebels hope their leader Salva Kiir can defeat President Bashir in the polls.
A referendum is also due in 2011 on whether the south should seek independence.