Photo/Illutration Chief Cabinet Secretary Yoshimasa Hayashi during a July 22 news conference in Tokyo (Takeshi Iwashita)

A Japanese man in his 20s who joined Russian forces fighting in Ukraine died last month in the Donetsk region of eastern Ukraine, sources said.

Chief Cabinet Secretary Yoshimasa Hayashi told a July 23 news conference the man was a former member of Japan’s Self-Defense Forces.

Hayashi, however, did not give the man’s name or say whether he died in battle.

Sources close to the Foreign Ministry said it was the first reported death of a Japanese national in the conflict.

The sources said the man died on June 3. Russian authorities notified the Japanese Embassy in Moscow of the fatality on June 5, and the embassy confirmed his identity by July 15.

The Foreign Ministry knows of several Japanese nationals fighting alongside Russian forces, the sources said.

Hayashi made no mention of other Japanese volunteers joining the fighting, saying, “It is a delicate matter.”

“We don’t have any information on injuries of Japanese nationals, other than this man,” he added.

(This article was written by Nen Satomi and Shohei Sasagawa.)