The Russian government has forced thousands of migrants and foreign students to fight alongside Russian troops in its war against Ukraine, adding extra manpower for its offensive in the Kharkiv region.

According to Bloomberg, Russian officials have with increasing frequency been threatening not to extend the visas of African students and young workers unless they agree to join the military, according to officials familiar with the matter using the tactics first deployed by the Wagner mercenary group,

Moscow launched a new offensive on May 10 in Kharkiv Oblast, where it reportedly managed to advance as far as 10 kilometers (6 miles) before Ukraine halted the advance near the first line of defense.

On June 8, President Volodymyr Zelensky said that Russian troops had failed their Kharkiv Oblast offensive.

It was reported that the Russian officials have been threatening African students and young workers not to extend their visas unless “they agree to join the military.”

While Russia has also been enlisting convicts, some Africans on work visas “have been detained and forced to decide between deportation or fighting.”

“Some of those people had been able to bribe officials to stay in the country and still avoid military service,” the report reads.

This is not the first time the Russian military is reported to have started bringing prisoners, migrants, and foreign nationals into its ranks.

Last September, the U.K. Defense Ministry reported that Russia was stepping up its campaign to recruit foreigners in neighboring countries and exploited migrant workers for its war against Ukraine.