North Korea is acknowledging that one of its naval vessels sank last month, killing an unspecified number of officers and sailors.
The state media dispatch said the submarine chaser was performing "combat duties." Saturday's report gave no other details such as a cause of the sinking.
State media showed leader Kim Jong Un visiting a "cemetery of fallen fighters."
Much of North Korea's military equipment is decrepit. But it has a massive army and thousands of artillery pieces deployed along its border. The rival Koreas have fought several bloody naval skirmishes along their disputed western sea boundary since 1999.
South Korea also blames Pyongyang for a 2010 torpedo attack that killed 46 South Korean sailors. A North Korean artillery attack that year killed four South Koreans on a frontline island.