A Japan Ground Self-Defense Force helicopter with 10 personnel aboard went missing in waters off the southern prefecture of Okinawa on Thursday, with what could be parts of the chopper later found in the sea.

The UH-60JA multipurpose helicopter is believed to have been caught up in an accident, Gen. Yasunori Morishita, chief of staff of the GSDF, told a press conference, as rescue efforts continued for the pilots, mechanics and other members of the Self-Defense Forces.

The helicopter disappeared from radar around 3:55 p.m. near Okinawa Prefecture's Miyako Island, shortly after taking off from there to surveil nearby land features, according to the GSDF.

File photo shows a UH-60 helicopter. (Photo courtesy of Japan's Ground Self-Defense Force)(Kyodo) 

The chopper was originally scheduled to return to Miyako Island at 5:05 p.m.

The Japan Coast Guard said it dispatched patrol ships to nearby waters, and retrieved a lifeboat that apparently belongs to the GSDF. It was found in a folded state, carrying no one on it, the coast guard said.

According to a coast guard source, oil and objects including what could be part of a rotor blade were found in the sea area where the accident is believed to have occurred.

Rough weather conditions were not reported around the time the helicopter went missing.

"We are putting maximum priority on human life and rescue operations," Prime Minister Fumio Kishida told reporters in Tokyo.

Japanese Prime Minister Fumio Kishida meets the press at his office in Tokyo on April 6, 2023, after a GSDF UH-60JA multipurpose helicopter with 10 personnel aboard went missing in waters off the southern prefecture of Okinawa earlier in the day. (Kyodo) ==Kyodo

The helicopter belongs to a unit under the GSDF's 8th Division based in Kumamoto Prefecture, which is in charge of the defense of the southwestern main island of Kyushu.

Lt. Gen. Yuichi Sakamoto, the 55-year-old commander of the division, was among those who were on board.

Located about 400 kilometers east of Taiwan, Miyako Island is home to a GSDF missile unit. It is adjacent to the East China Sea and close to the Japanese-controlled Senkaku Islands, which are claimed by Beijing.

As of March last year, the GSDF had 40 UH-60JA helicopters, which can carry up to 14 people and are often used for transporting emergency patients from remote islands and areas that have suffered a natural disaster.

In 2016, six people were killed after an Air Self-Defense Force U-125 flight inspection plane crashed on a mountain in the southwestern Japanese prefecture of Kagoshima, one of the deadliest accidents involving an SDF aircraft in recent years.

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