It's not just convicts. Russia is forcing its African migrants and students to fight for them in Ukraine.

• Russia is replenishing its troops with an unlikely source — African migrants and students.
• Thousands of Africans have been forced to join in Russia's war against Ukraine, per Bloomberg .
• The country has also been plugging its manpower gaps by sending prison inmates to the battlefield.

Russia is forcing thousands of African migrants and students to join in their war efforts against Ukraine, Bloomberg reported on Sunday, citing assessments from European officials.

According to Bloomberg's report, Russian officials have threatened not to renew the visas of African migrant workers and students if they didn't join the Russian Armed Forces.

Some African workers have even been threatened with deportation if they do not agree to fight in Ukraine, one European official told Bloomberg. Others have resorted to bribing Russian officials to stay out of the conflict, per the outlet.

A spokeswoman for Russia's foreign ministry did not respond to Bloomberg's request for comment.

This wouldn't be the first time the country has turned to unorthodox and controversial recruitment measures to replenish its troops.

Russia's reliance on attrition warfare has seen it continually drawing on its prison population to fuel its war effort.

In October, Russia's Deputy Justice Minister Vsevolod Vukolov said the country's prison population had plunged to a historic low of 266,000, per The Washington Post . Russia's prison population stood at 420,000 before the war.

In fact, Russia has recruited so many inmates that it has started to close down some of its prisons .

A local official told lawmakers in March that some prisons had to be shut down because of "a one-time large reduction in the number of convicts," per the Russian newspaper Kommersant .

But conscripting its migrant population could put further pressure on the Russian economy, which has been grappling with severe labor shortages .

"Unemployment is 3%, and in some regions, it is even lower," Russian Central Bank Gov. Elvira Nabiullina told lawmakers in November. "This means there are practically no workers left in the economy."

Representatives for Russia's foreign ministry did not immediately respond to a request for comment from BI sent outside regular business hours.