Ukrainian President Volodymyr Zelenskyy claimed that his country’s army has captured two Chinese soldiers fighting for Russia.

“These prisoners have documents, bank cards, and personal data,” he said.

“We have information indicating that there are significantly more Chinese citizens in the occupier’s units than just these two. We are currently verifying all the facts. Intelligence, the Security Service of Ukraine (SBU), and relevant units of the Armed Forces are working on this.”

He said that he has instructed the minister of foreign affairs of Ukraine to “immediately contact Beijing and find out how China intends to respond to this.”

“Russia’s involvement of China—whether directly or indirectly—in this war in Europe is a clear signal that Putin intends to do anything but end the war,” Zelenskyy said.

North Korea has sent thousands of its troops to Russia to support Moscow.

NIS said it monitored North Korean military movements and, on Oct. 18, reported that in early October, it had observed ships transporting 1,500 North Korean soldiers at a time to Vladivostok in Russia’s Far East.

Meanwhile, Zelenskyy confirmed for the first time on Monday that Ukrainian troops have been active in Russia’s Belgorod region.

In his nightly video address, he said Ukraine’s top commander, Oleksandr Syrskyi, had presented a report “on the front line, our presence in the Kursk region and our presence in the Belgorod region.”

“We continue active operations in the enemy’s border areas, and this is absolutely justified. The war must return to where it came from,” Zelenskyy said. “Our main objective remains the same: to protect our land and our communities in the Sumy and Kharkiv regions from Russian occupiers.”

Reuters contributed to this report.