KHARTOUM (Reuters) - Sudan's President Omar Hassan al-Bashir announced on Tuesday a two-week unilateral ceasefire in the country's main oil-producing state of Southern Kordofan, after weeks of fighting between government troops and rebels.
Southern Kordofan holds most of Sudan's remaining known oil reserves, after the country's south seceded last month, taking its oilfields with it.
Activists have accused Khartoum of launching airstrikes and attacks, targeting the state's ethnic Nuba group, in a bid to stamp out opposition in the wake of the independence of South Sudan.
The United Nations said tens of thousands have fled the violence and has called for an investigation into reports of human rights abuses in the territory, which borders South Sudan.
Sudan's government has dismissed the accusations and accused local armed groups, many of whom fought alongside the south during decades of civil war with the Khartoum government, of launching a rebellion to try and control the territory.
Bashir made an unannounced visit to the state on Tuesday, his first since the fighting broke out between Sudan's army and armed groups in early June.
"The government is committed to peace in Southern Kordofan," Bashir said in a speech broadcast on state radio, adding that following the two-week ceasefire, "the situation will be assessed on the ground".
Bashir said foreign organisations would not be allowed into the state and that any aid would be delivered only through the Sudanese Red Crescent organisation.
A report by the U.N. human rights office last week documented alleged violations in Kadugli and the surrounding Nuba mountains including extrajudicial killings, illegal detention, enforced disappearances, attacks against civilians, looting of homes and mass displacement.
The reports "if substantiated, could amount to crimes against humanity or war crimes," the United Nations said.
Sudan's government dismissed the report as "unfounded" and "malicious" and said last week it would form its own committee to assess the human rights situation there.
Opposition politicians said the fighting first flared after Sudan's army tried to disarm armed groups in Southern Kordofan. Political tensions were high after Bashir's National Congress Party won a state governorship election, in a vote that some opposition groups said was rigged.
Aid groups who were in the state before the latest fighting started reported both sides in the fighting prevented them from visiting areas hit by the fighting, making it difficult to verify reports.