By Francesca Hangeior.

Russia is allegedly sending thousands of migrants and foreign students to fight alongside its troops in the war against Ukraine for visa renewal, reports Bloomberg.

According to the Business news platform, the assessment was done by some European officials who alleged that the Kremlin is doing so to add extra manpower using the tactics first deployed by the Wagner mercenary group.

The report added that Russia has 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.

Moscow has also been enlisting convicts from its prisons while some Africans in Russia on work visas have been detained and forced to decide between deportation or fighting, one European official said. Some of those people had been able to bribe officials to stay in the country and still avoid military service, said the official, who, like other people cited, spoke on condition of anonymity.

Russia’s practice of sending migrants and students into battle under duress dates back to earlier in the war, another European official said. Those troops suffer especially high casualty rates because they are increasingly deployed in risky offensive maneuvers to protect more highly trained units, the official added.

A spokeswoman for the Russian Foreign Ministry didn’t respond to an email seeking comment.

According to reports citing Ukrainian intelligence, Russia has engaged in a global recruitment drive to enlist foreign mercenaries in at least 21 countries, including several nations in Africa. Army recruitment campaigns offer lucrative signing bonuses and salaries for those who’ll join up as contract soldiers. Recruiters have also targeted migrants and students who previously looked for employment in Russia, and in some cases have lured others over with promises of lucrative work before forcing them to train and deploy to the front.

Russia’s ability to mobilize far greater numbers of troops could become a significant factor in the war as President Vladimir Putin seeks to capitalize on a shift in momentum this year.

For now though, his forces have been grinding forward only slowly in northeastern Ukraine and suffering heavy losses, despite a shortage of troops and ammunition on the Ukrainian side.

The Russian military lost more than 1,200 people a day during May, according to the UK Ministry of Defence, its highest casualty rate of the war. Since the beginning of the invasion, Russia has seen some 500,000 personnel killed or wounded, the UK estimates. Bloomberg is unable to independently verify these figures.

At a meeting with foreign media in St. Petersburg late Wednesday, Putin appeared to imply that about 10,000 Russian troops a month are being killed or wounded and that Ukrainian losses are five times higher.

While the Kremlin has failed to achieve a breakthrough on the battlefield, it has stepped up a bombing campaign against Kharkiv, Ukraine’s second-largest city. Western officials say those attacks appear designed to make the city uninhabitable.