Two members of the security service of Ahmad Kadyrov, the head of the Chechen administration, died when the car with the bodyguards was blown up on Monday in Grozny.
According to the preliminary information, two of the bodyguards died at once, and two more, with one in critical condition, were taken to hospital.
All wounded were local residents, doing their military service in a special squad of Russian Defense Ministry. The investigation commission is currently clearing the details.
The choice of the city of Helsinki is not incidental as the capital of Finland had hosted US-Soviet negotiations on the limitation of nuclear stockpiles in 1969