A police van caught fire in Voznesensky Lane in central Moscow, a source in the emergency services said.
"Nobody was injured. The fire was extinguished at 14:30," they explained.
According to initial reports, a technical malfunction is the reason behind the blaze.
The "Baza" Telegram channel shared a photo of the van after the fire had been put out.
This comes amid ongoing unauthorised protests by supporters of Russian opposition vlogger Alexei Navalny in Moscow, Saint Petersburg, and other major Russian cities.