Around 4,000 of the 11,000-men contingent North Korea sent to Russia last year are thought to have died already, with more losses expected.

North Korean troops have not been seen on the frontlines in Russia’s Kursk region for several weeks, a Ukrainian military official said Friday, amid reports of mass casualties among Pyongyang’s forces.

The spokesman did not say how long that front line was. And while this is not the full picture, it does suggest significant North Korean casualties. Separately, the New York Times also reported that the North Koreans had been pulled off the front lines.