The army has been fighting rebels of the SPLM-N in South Kordofan bordering newly-independent South Sudan since June.

"We are holding 29 Chinese workers after a battle with the army yesterday," a spokesman for the SPLM-N said. "They are in good health. We are holding them for their own safety because the army was trying to strike again."

The army said rebels had attacked the compound of a Chinese construction company and captured 70 civilians.

"Most of them are Chinese. They are targeting civilians," said army spokesman Sawarmi Khalid Saad. He said there had been no battle in the area, adding that the army was now trying to rescue the civilians.