Search and rescue efforts are in progress following a US special operations aircraft crash off the coast of Yakushima Island in Japan on Wednesday.

The incident involved an Air Force CV-22B Osprey from the 353rd Special Operations Wing, carrying eight airmen, during what was described as a “routine training mission” by Air Force Special Operations Command. While the Japanese Coast Guard reported at least one fatality, US officials have yet to confirm this information, and the status of the crew remains unknown. Family notifications are ongoing.

Emergency personnel are actively conducting search and rescue operations, with the cause of the mishap currently undetermined, according to Air Force Special Operations Command.

The Japanese Coast Guard was alerted to the crash around 2:47 p.m. local time. Following the incident, the government of Japan’s Okinawa Prefecture requested the grounding of all Ospreys in the island chain due to safety concerns, though no official stand-down order has been issued by the US military.

Expressing regret over the incident, Okinawa Gov. Denny Tamaki emphasized concerns about the safety of Ospreys during a news conference.

The Osprey is capable of long-range infiltration, exfiltration, and resupply missions for special operations forces, handling tasks requiring both rotary-wing and fixed-wing aircraft capabilities.

Notably, the Osprey has faced historical mechanical and operational challenges leading to service member fatalities since 1992. This incident follows a similar crash a few months ago, where three US Marines lost their lives in an MV-22B Osprey during a military exercise in Australia.

Despite its history, the V-22 has a lower mishap rate compared to other aircraft. The Marine variant, MV-22, reportedly has a mishap rate of 3.16 per 100,000 flight hours, as stated by Marine aviation spokesman Maj. Jorge Hernandez in 2022.

This incident occurs approximately two weeks after the tragic training flight crash in the eastern Mediterranean Sea that claimed the lives of five Army special operations aviators.