Khartoum - Rebels from Sudan's Darfur region said they clashed on Sunday with government forces in embattled South Kordofan state, where other insurgents reported repulsing a government offensive.
The fighting is the latest since Sudan and South Sudan - which Khartoum accuses of backing the rebels - last week resumed African Union-led talks in Ethiopia to resolve security and other crucial issues.
Darfur's Justice and Equality Movement (JEM) said 10 government soldiers were killed in the fighting between El Muglad and El Dibb, in north-western South Kordofan just over the border from Darfur.
“Some on our side were wounded but nobody killed,” said JEM spokesperson Gibril Adam Bilal.
Casualty claims are difficult to verify, with access to South Kordofan restricted.
Army spokesperson Sawarmi Khaled Saad denied that a clash had occurred and said the JEM does not have “any presence or activity in South Kordofan state”.
The JEM began its Darfur uprising almost a decade ago.
Last year they and other Darfur insurgents joined a Revolutionary Front to work together to overthrow the Arab-dominated Khartoum regime that they say is unrepresentative of the country's diversity.
Another Revolutionary Front member, the Sudan People's Liberation Movement-North (SPLM-N), is active in South Kordofan and Blue Nile states.
SPLM-N on Sunday said it had repulsed government soldiers who tried to seize two rebel-held villages near the South Kordofan state capital of Kadugli.
The army tried on Friday to take Dloka village, 13km south of Kadugli, as well as a second community northeast of the government-controlled capital, SPLM-N spokesperson Arnu Ngutulu Lodi said.
“They have tried many times to control these areas,” which, he told reporters, have been in SPLM-N hands since fighting began in June last year.
Lodi said battles for the two villages left nine government troops and one rebel dead.
The army's Saad said a clash occurred in the area but the rebels were defeated.
Both the military and SPLM-N earlier agreed there had been fighting on Thursday at another location, Hajar Al-Dom village northeast of Kologi town, but disputed what had happened.
Ethnic minority insurgents from the SPLM-N previously fought alongside the rebels from southern Sudan who waged a 22-year civil war which ended in a 2005 peace deal that led to South Sudan's independence last year.
Sudan accuses South Sudan of working with the JEM and of backing the insurgencies in South Kordofan and Blue Nile.
The South denies supporting the rebels, but suspected JEM fighters were seen alongside its troops during fighting between Sudan and South Sudan along the disputed border in April.
Those battles sparked fears of wider war and led to a United Nations Security Council resolution which ordered a ceasefire and the AU talks which resumed last week.
In early August, negotiations led to a breakthrough deal on fees due by Juba for shipping its oil through the north's pipeline for export. But Sudan says the oil deal will not be implemented unless security issues are settled first.
The US ambassador to the United Nations, Susan Rice, on Thursday said Sudan's refusal to accept a demilitarised zone with South Sudan risks sparking “outright conflict”.
Rice said it was “equally disappointing” that Khartoum refused to implement the oil accord until all differences between the two have been settled.
South Sudan has agreed to an AU map of the demilitarised zone, but Khartoum has not. Its opposition has focused on the inclusion of a disputed area south of the Bahr el-Arab/Kiir River.
Britain has backed AU and UN calls for Khartoum to accept the map, saying it has no bearing on the line of a permanent border.
More than 650 000 people have been displaced or severely affected by the fighting in South Kordofan and Blue Nile, the United Nations says. - Sapa-AFP