Several Ukrainian soldiers told CNN that they are facing a new threat on the front line as the Russian military has increased its use of chemical weapons in recent weeks.

A military doctor told American television that in recent weeks, 9 separate cases of the use of this weapon by the Russians were recorded in the front-line area around the city of Orihiv, in the Zaporizhzhya region, controlled by the Ukrainian armed forces.

Russian invasion forces have been unable to capture the city since the invasion began last year, but have resumed a sustained bombardment here since October.

A Ukrainian military medic told CNN that caustic and flammable gas was dropped from drones onto Ukrainian trenches, resulting in one injury.

Injured soldiers say the gas was used to cause panic, and that after it is dropped on their positions, Russian forces resume regular bombardment or launch drone strikes.

A Ukrainian intelligence official told CNN that the substance used by the Russians was a type of CS gas, a tear gas commonly used by law enforcement as a means of neutralizing violent protesters.

The use of such gases in theaters of war is prohibited by the UN Convention on Chemical Weapons.

What do gassed Russian soldiers say?

There have been sporadic reports of Russian invasion forces using gas on the battlefield in recent months, but reports of its use around Orichov are remarkably consistent.

Two soldiers who survived one such attack showed CNN reporters medical records showing they had been poisoned.

“At first I saw smoke. I ran out of the trenches, and the gas suddenly ignited. The trenches were burning. This gas burns, blinds, it is impossible to breathe, it immediately goes into the throat. I didn’t have even a second at my disposal,” said one of them.

“You shoot twice in the chest, and then you can’t breathe,” added the second Ukrainian serviceman.

Both soldiers reported injuries, including burns and rashes on their faces, as well as their mouths and throats. CNN correspondents confirmed that the soldiers’ faces were left with traces of these wounds.

The Ukrainian soldiers’ accounts add yet another concern to a growing list of issues raised by their commanders, with President Volodymyr Zelenskyy expected to hold a news conference on Tuesday amid visible tensions with the military leadership in Kyiv.

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