An explosion took place in St. Petersburg subway, killing 10 people,- BBC reports.

Reportedly, the incident reportedly happened at the Sennaya station. As the witnesses say, the explosive device was installed in the subway car.

Official agencies do not specify number of victims. However according to Russian Media, the death toll is up to ten.

Metro stations have been closed, the movement of trains is suspended.
Nearly 80 paramedics are working on the ground and reportedly, additional forces should be mobilized.

The Russian president states that the reason of explosion is still unknown. The investigation works on several versions, including a possible terrorist attack.