Fresh fighting has flared between Arab nomads and former southern rebels in an oil-rich border between north and south Sudan, First Vice President Salva Kiir said on Monday.
The clashes began on Sunday, a week after fierce gunbattles left around 70 dead and displaced more than 100.
"Yesterday...instead of fighting in Northern Bahr al Ghazal, (they are) fighting in Unity State," Kiir, who is also the leader of south Sudan, told a governors’ forum in the southern capital Juba.
"There was very serious fighting there," he added.
Unity State, which produces a huge amount of Sudan’s oil, borders Northern Bahr al Ghazal state, home to the oil-rich region of Abyei whose status is not yet decided despite the 2005 peace agreement between north and south Sudan.
No information on casualties was immediately available.
Kiir said Misseriya tribesmen want people in the south to take up arms and fight in order to provoke a full-scale war.
"The fighting lasted the whole night, and they (the southern army or Sudan People’s Liberation Army) fought back up to this morning," Unity State governor Taban Deng told AFP on the sidelines of the forum.
Fighting first erupted in December, near the disputed oil areas, leaving up to 100 dead, when Khartoum-backed Baggara Arab militia attacked a southern army garrison, after it refused to allow armed nomads into the south.
The clashes ended after Kiir told his forces to let the nomads move south and graze their animals, with hopes that they would return to the north during the dry season.
Relations between the Khartoum authorities in the northern, mainly Arab part of Sudan, and Kiir’s SPLM have remained tense despite their power-sharing arrangement that followed the 2005 Comprehensive Peace Agreement that ended a civil war.
The key sticking points are the status of the Abyei oil region and where the north-south border will be drawn.
Under the terms of the CPA, elections are due in 2009 and a referendum two years leter will allow southerners to say whether they want to continue with the north or become an entirely independent state.