Darfur's rebel Justice and Equality Movement said on Sunday it had seized a Sudanese government military base close to the border with Chad, stoking tensions after a series of clashes in the area, Reuters reported.
Joint U.N.-African Union peacekeepers in Darfur confirmed Sudanese government soldiers were attacked on Saturday afternoon in the town of Kornoi, which is on a key road in North Darfur, and condemned the violence. No one was immediately available to comment from the Sudanese army.
The report was the latest sign of growing insecurity in remote North Darfur that has been worsened by deteriorating relations between Sudan and its neighbor Chad.
Sudan's government says JEM is backed by Chad, while Chad accuses Khartoum of supporting insurgents in its territory.
JEM clashed with former rebels backed by Sudan's government earlier this month close to the town of Umm Baru -- just 50 km (30 miles) away from Kornoi along a strategic route which stretches southeast from the Chadian border into Darfur.
Sudan also accused Chad of launching three airstrikes inside Sudan, further south over their shared border, on Friday and Saturday.
"JEM has taken Kornoi. We attacked a garrison there. We want to clear them out of the area," JEM leader Khaili Ibrahim told Reuters by satellite telephone, saying the two-hour battle had taken place late afternoon on Saturday.
"We now control a very large area. JEM will proceed to control the whole area - the whole of Darfur, including the capitals (El Fasher, El Geneina and Nyala, the capitals of the states of north, west and south Darfur)."
Ibrahim said there had been casualties on both sides, but it was too early to release statistics.
The joint UNAMID peacekeeping force said it had given water and medical care to some government soldiers who came to two of its nearby bases after the attack.
UNAMID's Joint Special Representative Rodolphe Adada released a statement condemning the attack, adding "I call on all the parties to the Darfur conflict to refrain from the use of violence, to seek a peaceful resolution to their problems."
UNAMID communications chief Kemal Saiki said he could not confirm the identity of the attackers who now appeared to be in control of the area around Kornoi.
There have been signs that JEM has been re-arming and re-grouping in recent months. Diplomatic sources in Khartoum have said JEM may be planning a major offensive in Darfur, partly in retaliation for an incursion by Chadian insurgents into Chad earlier this month, which N'Djamena said was backed by Khartoum.
JEM was one of two major insurgent groups which took up arms against Sudan's government in 2003, accusing Khartoum of neglecting the remote western region.
The United Nations says up to 300,000 people have died in the Darfur conflict, which escalated after government soldiers and allied militias set out to crush the rebellion. Other international experts have put the death count at 200,000 while Khartoum says just 10,000 have died.
JEM, which says it intends to control Darfur and the neighboring regions of northern and southern Kordofan, also launched a shock attack on Khartoum last year, saying it wanted to overthrow the government.
JEM has been holding a series of discussions with Sudan's government in Qatar. But they have so far not evolved into full peace talks.