MOSCOW, December 30. /ITAR-TASS/. The power of the explosion at a trolleybus in the southern Russian city of Volograd was equivalent to at least 4 kg TNT, Russian Investigation Committee spokesman Vladimir Markin said.

15 people were killed and 27 remain in hospitals as a result of a bomb attack in a trolleybus in Volgograd, Russia’s Public Healthcare Ministry reported.

Five of the injured died in hospital, raising the death toll from initial 10 to 15. Latest reports from Public Healthcare Ministry say that there are 27 people in hospitals.

On Monday, the attack occurred in a rush hour on one of the city’s busy streets. As reported by Itar-Tass newsperson from the site of the incident, the blast occurred on Katchintsev Street of Volgograd’s Dzerzhinsky district.

According to Investigative Committee spokesman, the attack in Volgograd’s trolleybus was carried out by a suicide bomber.