A search is underway for the crew of a Japan Ground Self-Defense Force helicopter that went missing off the coast of an island in the southwestern prefecture of Okinawa.

The Defense Ministry says a UH-60JA multi-purpose chopper vanished from radar while flying over waters north of the island of Miyakojima at around 3:56 p.m. on Thursday.

It says the helicopter was carrying 10 personnel, including the head of the GSDF's 8th Division, to which the craft belongs.

The ministry says the helicopter left a base on Miyakojima at 3:46 p.m. and was scheduled to return at 5:05 p.m.

It says wind velocity, visibility and other weather conditions near the island were good enough for a helicopter flight, and that the crew was checking its surroundings visually.

Coast guard officials say their search has discovered what appear to be parts of the chopper in or near waters where it went missing. It has also found oil floating on the water surface.

The Defense Ministry says it is trying to confirm whether the parts are from the helicopter.

The ministry says the incident was likely an accident, and has set up an accident investigation committee at the GSDF.

GSDF Chief of Staff General Morishita Yasunori apologized at a news conference on Thursday. He said the GSDF will continue doing everything it can to find and rescue all personnel of the helicopter as soon as possible.

The GSDF has grounded all its helicopters of the same type nationwide, except for disaster dispatches and other incidents.