Kim expressed satisfaction, saying, "Bullets seemed to have their eyes, and they were crack shots never missing targets" after watching automatic rifle firing by combatants of the special operation battalion under the direct control of KPA Unit 525, it said.

The contest is viewed as a drill for the North Korean military's rear area infiltration into South Korea via helicopter, experts say.

There is speculation that North Korea could soon conduct its sixth nuclear test or launch a long-range rocket around key anniversaries in April.

The country will mark the 105th birthday of late founder Kim Il-sung on Saturday, and April 25 is the 85th anniversary of the KPA's creation.

The United States has sent the Carl Vinson aircraft carrier strike group again toward the Korean Peninsula in an apparent effort to counter North Korea's threats. The North vowed to take tough countermeasures, calling the dispatch a "reckless" act.

Concerns are also growing here that the US may conduct a pre-emptive attack on the North similar to its latest airstrike against Syria.

Washington has said "all options" are available, including possible military actions, to counter North Korea's threats.

In December, KPA Unit 525 conducted a simulated drill aimed at destroying South Korea's presidential office and other specific targets, which was also observed by the North's leader.

Seoul and Washington are conducting two-month joint military drills that will wrap up at the end of April. North Korea called the move an operation intended to "decapitate" the North Korean leadership. (Yonhap)