Gunmen have kidnapped three workers including a Chinese and an Algerian from an oilfield in Sudan's West Kordofan province, the army said.
"Armed men [on Friday] attacked the Kanar field in West Kordofan and abducted three workers," army spokesman Sawarmi Khaled Saad said.
He added that three attackers were killed in a firefight with guards at the site. No further details were immediately available about the kidnapping.
West Kordofan borders the province of South Kordofan, where Sudanese government forces have been battling rebels for nearly three years.
The clashes in South Kordofan and Blue Nile states with fighters of the Sudan People's Liberation Movement-North have displaced or severely affected 1.1 million people, the United Nations says.
West Kordofan also borders Sudan's western region of Darfur, where the army and allied tribes have since 2003 battled rebels demanding an end to the region's economic marginalisation and power sharing with the Khartoum government.
China is the main investor in Sudan's economically vital oil sector.