Clashes between Sudan’s government and rebels in South Kordofan province on Tuesday smashed a months-long lull in fighting, the two sides said.
Ethnic minority rebels in the southern state who say they are politically and economically marginalised have been fighting the Arab-dominated government since 2011.
Fighting there and in Darfur and Blue Nile states have left thousands dead and millions displaced.
Khartoum announced a unilateral ceasefire in June, which it extended by six months in January.
Army spokesperson Brigadier Ahmed Khalifa al-Shami said on Tuesday that rebels “today attacked one of our positions in the area of Mshayish, 38km west of Kadugli,” the capital of South Kordofan.
“We pushed them back and lost one of our men, while 10 others were injured,” he told AFP.
He said rebels have carried out several attacks in recent days, but that government forces were respecting the ceasefire.
The rebel Sudan People’s Liberation Movement-North (SPLM-N) said the army had attacked one of its positions.
The government was “launching today its summer campaign despite the announcement of a ceasefire by President Omar al-Bashir,” said SPLM-N spokesperson Arnu Lodi.
He did not report any casualties.
An army statement referred to “heavy human and material casualties suffered by the rebels” without giving further details.
South Kordofan and Blue Nile were no-go areas and thousands of people were without access to humanitarian relief, the top UN aid official in the country said last week.
Marta Ruedas said aid workers were now able enter the most war-torn parts of Darfur, where the UN says fighting has killed more than 300 000 people and displaced 2.5 million since 2003.
But aid is still blocked from Blue Nile and South Kordofan, she said.
Conflicts over access to resources have complicated the insurgency and created further instability in the region.
In East Darfur, tribal clashes killed more than 20 people and wounded dozens in the Abu Karinka zone on Monday, an official and witnesses said.
The region sees regular tribal clashes and violence linked to banditry.
