Seven people, including two children, were injured in an explosion near the Semyonovskaya metro station when a valve flew off a fire extinguisher in a freak accident, Moscow police said.
The incident occurred around 7 p.m. Monday at the cafe at 3 Shcherbakovskaya Ulitsa, across from the Semyonovsky mall, while workers were carrying out a 50-liter fire extinguisher.
"During transportation, the valve flew off, causing the bottle to move around chaotically causing damage and injuries," police representative Tatyana Petrova told Interfax
The blast broke the windows of nearby buildings but a fire did not break out, the report said.
The injuries consisted mainly of shrapnel wounds and cuts. None were life-threatening.
Earlier, police said that nine people were injured and that the blast had been caused by a gas cylinder falling to the floor and exploding, as a result of rough handling.
It was later revealed to have been a fire extinguisher that exploded.
Investigators were working at the scene Tuesday to determine the exact circumstances of the incident.
A criminal case into possible violations of safety rules has been opened.
On May 9, a gas cylinder exploded on a bus parked outside the metro station at Rechnoi Vokzal in the north of the city, injuring two people.
Correction: An earlier version of this article incorrectly stated that the explosion took place in a Shokoladnitsa cafe. The company has since issued an official statement saying that the explosion took place next door.