The head of Ukraine’s military intelligence authorities said eight-thousand North Korean troops are still fighting on the front lines in Russia’s Kursk region, disputing media reports that North Koreans have been pulled from the front. 

Kyrylo Budanov, the head of Ukraine’s Defense Intelligence Directorate, made the remarks in an interview with the U.S.-based website the War Zone.

In the interview, released Tuesday, Budanov said media reports that those troops have not been seen on the front lines in weeks are “wrong.”

But he said the number of North Korean troops has decreased and Ukraine is trying to find out why.

The New York Times reported last Friday that North Korean troops deployed to support Russia in battle against Ukrainian forces had been pulled from the front after suffering heavy casualties, citing unidentified officials from the United States and Ukraine.