The Sudan Tribune quotes Sudanese Armed Forces spokesman Al-Sawarmi Khalid Saad as saying that three workers, an Algerian, a Chinese and a Sudanese, were kidnapped.

The kidnapped personnel were working for the Greater Nile Petroleum Operating Company.

While the SAF stated the gunmen's identity was unknown, sources accuse the rebel Justice and Equality Movement for the attack, naming Hashim Ginzeer as the commander of the JEM force.

Those sources also say the abductees have been taken to the South Sudan's borders.

However, China's Xinhua newsagency reports two Chinese engineers working at the oil field were kidnapped.

It reports the emergency mechanism at the Chinese embassy in Khartoum has kicked into action, asking Sudanese authorities to guarantee the safety of the two Chinese engineers and ensure their release as soon as possible.

The Sudanese government has been fighting the Sudan People's Liberation Movement/North in South Kordofan state for almost three years. Its problems have intensified with the JEM moving into the region.