The request was made through China's top envoy to Seoul, Li Bin, during talks with Vice Foreign Minister Choi Young-Jin on Wednesday, the ministry said.

"Ambassador Li said he would report our request to his country," foreign ministry spokesman Shin Bong-Kil said.

Since mid-June hackers have broken into 211 computers at 10 government agencies, including the Korea Institute for Defense Analyses and the Agency for Defense Development involved in weapons development, officials said.

South Korea's parliament, the National Assembly, was among institutions targeted by the hackers. Yonhap news agency said e-mail IDs of parliamentary staffers and former and incumbent lawmakers had been stolen.

Intelligence officials said the hackers had used two information-stealing viruses, a variation of the Peep Trojan hacking program and Backdoor Revacc, since their first attack on June 13.

South Korean news media quoted intelligence and defense ministry sources as saying that one of the hackers was confirmed to be a student at a foreign-language school in southern China which is affiliated with China's People's Liberation Army.

However it was not clear if the student was also a member of the army, Yonhap said.

US forces stationed in South Korea on Thursday denied local press reports that hackers had attacked US military websites in South Korea and other countries in March.

SPACE.WIRE