"Presumably, a small handmade explosive device went off in front of Flat 222 on the first floor in 10 Bolshoi Gnezdikovsky Lane," said the source.
In his words, the explosion damaged the door to the flat, but left no victims.
Bomb disposal engineers of Moscow's interior affairs department were summoned to the site. The circumstances of the incident are being clarified. The blast thundered at 2 pm Moscow time on Monday.