Ukraine’s President Volodymyr Zelensky said Friday that several “seriously wounded” North Korean soldiers died from their injuries after being captured by Ukrainian forces.

A fragment of a note written by a North Korean soldier who died while deployed in Russia’s war against Ukraine suggests that Pyongyang may have sent convicts to support Russia. Ukraine’s Special Operations Forces revealed a memo allegedly written by a soldier identified as Jung Kyung-hong via Telegram on Dec.

Russia is deploying “human waves” of North Korean soldiers, the U.S. said, and one soldier captured by Ukraine died of his injuries. Others died by suicide.