The Metropolitan Prosecutor's Office announced this on its Telegram channel.

Reportedly, a 14-year-old teenager died on the spot, a man died in an ambulance. 

A 12-year-old boy was also injured.

The prosecutor's office is checking.

No other details are provided.

TASS, citing a source in the emergency services, reports that an explosive device of an unknown type, possibly a homemade one, was detonated in the apartment.