Updated

Two Russian taxi drivers were fired after a video of them forcing women to smear their faces with green antiseptic dye – allegedly as punishment for not paying – went viral.

A clip of the incident in the city of Khabarovsk was posted on YouTube. The dye, known as “zelyonka,” is difficult to remove but not usually harmful, according to the BBC.

Previously, the dye has been thrown at politicians opposed to Russian President Vladimir Putin.

The cab firm fired the drivers after a taxi drivers’ union demanded the dismissals, the BBC reports.

Police are still investigating the incident. The YouTube clip show one of the women trying to hide her green face, while her companion receives green dye to smear on her face.

It’s unclear whether the women didn’t have money to pay for their journey.

In March and April the same dye was thrown at Alexei Navalny, a leading critic of Putin; after the second attack, Navalny needed an operation on one of his eyes because the dye had been mixed with a caustic chemical. There have been a number of these attacks in Russia since 2008.