Search and rescue efforts are underway for a Marine pilot who ejected about 120 miles off the coast of Japan on Wednesday.

The pilot ditched his F/A-18 at approximately 6:40 p.m. local time southeast of Iwakuni, Japan, the Marine Corps said in a statement. The aircraft was assigned to 1st Marine Aircraft Wing based out of Okinawa.

The cause of the incident is under investigation.

It is the fourth Marine Corps F/A-18 to crash since July. In August, because of an increasing number of training mishaps, the Marines temporarily grounded their entire fleet of F/A-18s.

First debuted in the 1980s, the F/A-18 is a multi-role fighter and is primarily used by the U.S. Navy and Marine Corps. It comes in a number of variants with both single- and two-seat configurations and has been exported to a handful of U.S. allies, including Canada and Kuwait.

(c) 2016, The Washington Post · Thomas Gibbons-Neff