N Korea may conduct 4 more tests; US elections possible trigger date

North Korea was expected to conduct three to four more nuclear weapons tests, a South Korean politician said today amid hints from Pyongyang that it could be preparing for a second test.

"Checking reports by intelligence agencies of concerned countries, it is certain that North Korea will perform three to four additional nuclear tests from now on,'' said Chung Hyung-Keun, quoted by Yonhap news agency.

Mr Chung, a member of the South Korean parliament's intelligence committee, was deputy head of the Agency for National Security Planning, the forerunner of the National Intelligence Service, in the mid-1990s.

He was speaking on a local radio program.

Earlier this week, US media reports and Japanese Foreign Minister Taro Aso said the North appeared to be preparing for a second test following its first on October 9, which sparked United Nations condemnation and punitive sanctions.

The deputy head of North Korea's foreign ministry Li Gun, speaking to ABC News in Pyongyang, declined to directly confirm or deny the reports, but hinted that a test could be in the works.

"Even if there is a ... nuclear test, that is natural, so we don't have to care much about this issue. I think the test itself will be natural,'' he said.

Mr Chung noted suspicious activities in Kilju county in North Hamkyong province near the northeast coast of North Korea. The communist state conducted its first test in that area.

"The North initially dug two horizontal underground tunnels in Kilju, North Hamkyong Province - one on the east side and the other on the west side,'' Mr Chung said, adding that the first test was conducted on the east side.

"Now, the North is opening up the clogged tunnel on the west side as 30-40 workers have been showing up there every day and have built an interim building. They are preparing for a second nuclear test,'' he said.

Mr Chung said the second test would be conducted before the United States holds mid-term Congressional elections on November 7.

Seoul analysts also see the US elections as a possible trigger date.