An unknown attacker tossed a grenade into a nightclub in Moscow's northern outskirts early Thursday, injuring four people, and then fled.
The attack occurred around 2 a.m. at the Lotus nightclub on 2 Ulitsa Sofii Kovalevskoi, Interfax reported.
Two men and a woman received serious injuries and had to be hospitalized, and one was in critical condition. The fourth person escaped with less serious injuries that paramedics were able to treat on the spot.
The motive for the attack was unclear. Police told Itar-Tass that the grenade had been directed at a bookmaker's office located in the same building as the club. Interfax said security guards barred the suspect from the club because he was heavily intoxicated and in an ensuing brawl the perpetrator threw the grenade and fled.
With the help of CCTV footage, the police have made a composite sketch of the man who threw the grenade.
If caught, the attacker faces up to three years in prison on charges of intentionally inflicting damage to property and illegal weapons possession.