Five people have been killed in a helicopter crash at a South Korean marine base in the city of Pohang.
The helicopter, which was being test-flown after a repair, caught fire after it crashed to the ground from about 10 metres in the air, the country's defence ministry said.
One person survived the crash and was being treated at a nearby hospital.
The military will form a committee to investigate the cause.
Tuesday's crash was the second fatal accident involving South Korean military aircraft in recent months.
Pohang, in the country's south east, is not far from where a South Korean F-15K fighter jet crashed into a mountain in April, killing both the pilot and co-pilot.