SEOUL (AFP) - North Korea has announced it intends to carry out a live-fire drill on Monday near its disputed maritime border with South Korea, Seoul's defence ministry said.

"The North notified us that they would stage live-fire drills near the Yellow Sea border today," a ministry spokesman said.

It was not immediately clear when the exercise would take place, but the South's Yonhap news agency said the North's notification had warned the South to "control" its naval vessels ahead of the drill.

It is unusual for North Korea to notify the South ahead of a live-fire exercise, and the announcement comes at a time of simmering inter-Korean tensions. Pyongyang has carried out a series of rocket and short-range missile launches in recent weeks, in a pointed protest at ongoing annual South Korea-US military exercises.

On Wednesday it upped the ante by test-firing two mid-range ballistic missiles capable of striking Japan, sparking condemnation from the United Nations Security Council. The de-facto maritime boundary between the two Koreas - the Northern Limit Line - is not recognised by Pyongyang, which argues it was unilaterally drawn by the US-led United Nations forces after the 1950-53 Korean War.

The disputed border has been the scene of brief but bloody naval clashes in 1999, 2002 and 2009.