South Korea’s spy agency says North Korea appears to have sent additional troops to Russia, after its soldiers deployed on the Russian-Ukraine fronts suffered heavy casualties.

North Korea allegedly provided more troops to Russia for support in their war in Ukraine, according to South Korea’s spy agency. South Korea’s National Intelligence Service announced it detected new troop movements from North Korea but did not specify how many troops have been deployed to Russia recently.

The fresh deployment comes after North Korea suffered heavy casualties on the front lines in Russia’s war against Ukraine, the South’s spy agency says.