The North Korean military reportedly continues to be on high alert amid heightened tension on the Korean Peninsula over the sinking of the Cheonan warship.

In a report submitted to the parliamentary committee on national defense, the Defense Ministry said the North's military has maintained a heightened readiness since May 21st. In particular, the report said that ground-to-air missile radar activities were found to be active.

The report added that the North Korean military increased its anti-submarine drills at the East Sea from June 3rd as part of efforts to counter the South’s military.

The report says that exercises by the North’s ground forces have not been detected as they are dispatched to assist farmers in May and June.

The Defense Ministry also said that a total of 44 North Korean fishing vessels intentionally crossed the Northern Limit Line into South Korean waters 22 times since May 17th.