Authorities called off Tuesday a search and rescue operation for the five U.S. Marines who went missing after a fatal crash involving a fighter jet and a tanker plane off Japan's western coast last week.

The search was halted as there were no significant signs of the crash remaining, the Japanese Defense Ministry said. The crash occurred when an FA-18 fighter jet and KC-130 tanker plane based in Japan collided in midair while conducting training, including airborne refueling, early Thursday.

"It is with a heavy heart that we have shifted to recovery operations," said Lt. Gen. Jerry Martinez, commander of U.S. Forces Japan, in a statement. The Marine Corps pronounced the five aircrew deceased after a more than 800-hour search, according to U.S. Forces Japan.

The five Marines are believed to have been on board a KC-130 tanker plane. Two Marines on the FA-18 fighter were rescued on the day of the incident, but Capt. Jahmar Resilard, 28, has since died.

U.S. forces, Japan's Self-Defense Forces, the Japan Coast Guard as well as the Australian air force were involved in the search that covered some 90,000 square kilometers of area in the Pacific Ocean. The collision took place about 100 kilometers south of Cape Muroto in Kochi Prefecture.

The two aircraft belonged to Marine Corps Air Station Iwakuni in Yamaguchi Prefecture, western Japan. The U.S. military has categorized the crash as a "Class A" mishap, the most severe category on its scale of four.