A news report said the National Intelligence Service (NIS), Seoul's main spy agency, had told Mr Han that about 130,000 items of government information had been hacked over the past four years.

'According to an NIS report, the leakage of national secrets by hacking which originates in North Korea and China is very serious,' Mr Han told a cabinet meeting, according to a statement which gave no figures.

He blamed 'a loosening sense of security among public servants' who recklessly use data in personal computers or on the Internet.

Government offices have decided to conduct a monthly security check on computer systems as part of countermeasures beginning this month.

Mr Han's office did not disclose any details of the hacking or what type of information was obtained. The NIS would not comment.

Munhwa Ilbo, a Seoul-based newspaper, said on Tuesday the NIS report found about 130,000 extracts of 'important documents' were obtained by the Chinese and North Korean hackers.

The documents largely focused on foreign policy and national security, Munhwa said.

Both China and North Korea operate elite units of IT experts to launch an attack or hack into computer systems in other countries, it said.

South Korea is one of the world's most wired societies, with 80 per cent of households linked to the Internet. -- AFP