SEOUL, South Korea – North Korea says it has successfully conducted a nuclear test.

The country’s official Korean Central News Agency reported that the test was carried out Monday.

Lee Dong-kwan, a spokesman for the South Korean president, says that a nuclear test may have been carried out in the North.

President Lee Myung-bak has called an emergency security session.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP’s earlier story is below.

SEOUL, South Korea (AP) — South Korean media are reporting that North Korea may have conducted a nuclear test.

YTN television is citing an unnamed government official and the Yonhap news agency cites a ruling party member as saying the nuclear test may have occured Monday morning.

South Korean President Lee Myung-bak has convened an emergency meeting.