CAIRO ø Sudanese insurgents have begun targeting Chinese forces and laborers in the Arab League state.

Sudanese rebel sources said rebel forces have sought to drive out the large Chinese presence in Sudan. China has sent thousands of people to operate the oil fields and protect them from insurgency attack.

Western diplomatic sources estimated that China has deployed 4,000 troops to protect Beijing's oil interests in southern Sudan. The troops were said to have guarded Chinese facilities and helped Sudan in regional defense.

At least four Chinese nationals were abducted by the rebels over the last month. They were identified as security guards from the North China Construction Co. Two of the Chinese workers were killed and the others were returned safely. The bodies, identified as those of employees of the Liaohe Oil Field Road Cosntruction Co., were found on March 27.

Beijing said the two workers had been drilling water wells near Buram city in western Sudan. But rebel sources said the Chinese were two of thousands of mercernaries for the Khartoum regime.

The sources said they did not have evidence that Sudan employed Chinese troops to quell the revolt in the Darfour province. On Thursday, the New York-based Human Rights Watch reported that Sudan used Arab militias to destroy African villages and kill their in Darfour.

Human Rights Watch said Arab militias and Sudanese military troops killed 136 African men in Darfour in March. The group said the victims were members of the Fur ethnic group who were rounded up and executed in two separate government and Janjaweed militia operations on March 5.

"The Janjaweed are no longer simply militias supported by the Sudanese government," Kenneth Roth, Human Rights Watch's executive director, said in a statement. "Operations carried out by the Janjaweed often enjoy air support from the government of Sudan, both aerial bombardment before operations and helicopter reconnaissance afterwards to ensure the area is empty."