Sudan's ruling National Congress Party (NCP) on Sunday condemned the attack launched by Sudan People's Liberation Movement (SPLM) on a site of a Chinese company in South Kordofan, official SUNA news agency reported.

The agency quoted Haj Majid Suwar, the NCP political mobilization secretary, as saying "the attack constitutes a violation of all international laws and norms including those effective during war times."

Suwar held South Sudan government and the ruling SPLM responsible for the bloodshed caused by the rebels, who are led by the SPLM's northern sector in the states of Blue Nile and South Kordofan.

"The hands of the SPLM, Sudan People's Liberation Army (SPLA) and the South Sudan government are stained with the blood of the citizens of South Kordofan and Blue Nile because they keep providing support to the SPLM's northern sector," he said.

The secretary added that South Sudan is responsible for the Chinese workers being held captive and the displacement and killings of innocent citizens for its support to the rebels in South Kordofan.

He further said efforts are underway to secure the safety of the abducted Chinese nationals and to rescue them as soon as possible.

The Chinese Embassy in Khartoum confirmed earlier Sunday that more than 20 Chinese nationals were missing after an attack by rebels on a camp belonging to a Chinese company operating in South Kordofan.

An official at the Chinese embassy told Xinhua that "the embassy has started implementation of the emergency mechanism to follow up the issue and made contacts with the Sudanese authorities in this respect."

South Kordofan, located on the Sudan-South Sudan border, has been witnessing armed clashes between the Sudanese army and the SPLA's northern sector since June last year.