Chinese hostages 'killed' by Sudan kidnappers(CNN) -- Five of nine abducted Chinese oil workers were killed Monday by their kidnappers in Sudan, a Sudanese official told CNN.
Two others were injured and managed to flee, while two others remained in captivity, said Foreign Ministry spokesman Ali Sadiq.
China's state-run news agency reported the same findings, citing the Chinese Embassy in Sudan.
The workers for the China National Petroleum Corporation had been kidnapped by "unknown militants" in the Southern Kordofan state of central Sudan, the Xinhua news agency reported, citing the Chinese Embassy in Sudan.
China has invested heavily in Africa, particularly in oil-producing countries such as Sudan.
Trade between Africa and China doubled in recent years, and China became the continent's second-largest trading partner, doing business worth $73 billion in 2007, according to a report from the Council on Foreign Relations in New York.
China gets about a third of its oil from African countries, mainly Angola, the Republic of Congo, Equatorial Guinea and Sudan, the report says.
Human rights groups have said that China's commercial ties with Sudan provide the Sudanese authorities with revenue that it uses in attacks on civilians in the western Darfur region.