SEOUL - SOUTH Korean police were on Wednesday investigating a series of cyber attacks on major websites including those for the presidential office, the defence ministry and other government agencies.

Some 25 websites were attacked late on Tuesday evening, shutting off service for nearly four hours, media reports said.

The Cyber Terror Response Center, a division of the National Police Agency, has established a team to look into the case, according to Yonhap news agency.

The so-called denial-of-service attacks targeted government ministries, agencies and major Internet portal sites, Yonhap quoted officials at the state-run Korea Information Security Agency as saying.

Denial-of-service attacks involve the sending of large amounts of data that cause web servers to seize up.

The Defence Security Command last month reported that the nation's military computer networks are under ever-growing cyber attack, with 95,000 cases reported daily on average.

It said in a report that every day the military counters an average of 10,450 hacking attempts and 81,700 computer virus infections in addition to other cases.

The command said most of the attacks are the same as ordinary people experience at home, but 11 percent are sophisticated attempts to hack into military servers and gather intelligence. -- AFP