MOSCOW, July 8 (Itar-Tass) —— The explosive device which went off in a building in Moscow overnight was left by someone on a windowsill on the ground floor, the Moscow police press service said.
The blast occurred in Building 24, Sydakova Street in Moscow at 04:30 Moscow time this Sunday.
The explosive device without a cover was left by someone on the sill, the source said.
Two people with injuries from broken glass were taken to hospital. One of them is in moderately grave condition.
The blast damaged 20 windows in the building.
An investigation into the incident is underway.