A blast ripped through a Central Asian-themed cafe in the Russian city of Voronezh on Monday, shattering windows, Russian news agencies reported, citing local police.
The shattered windows of the "Eastern Tea House" on Lenin Street were shown in footage published by the Zvezda news service.
The Mash media group said the cafe was attacked in the early hours when no one was on the premises.
RIA state news agency quoted police as saying they were investigating after reports about damage at the cafe.
Another explosion
Last month, there was another mysterious explosion in Russia, in St Petersburg.
On March 2, two buildings were damaged, and people were evacuated in Russia's St Petersburg after residents reported a loud explosion that blew out windows.
There were no casualties in this incident, although residents reported they heard strange sounds followed by a blast and a fire. The cause remains unknown, although it is suspected that it is from a drone attack.
Drone attacks have frequented the Russian city of Voronezh throughout the war between Russia and Ukraine, as recently as January.