Russian police are hunting for two suspects in the wake of a bomb blast in the St Petersburg metro system that killed at least 11 people and wounded 45 more.
Law enforcement officials have said that a suicide bomber was responsible for the blast, according to reports in Russian media.
The suspected bomber is thought to have links to radical Islamists and is believed to be a 23-year-old from central Asia.
Definitive conclusions cannot be made until DNA is examined but there are reports the attacker carried the bomb in a backpack.
An unidentified explosive device went off at 2:20pm on a train after leaving Sennaya Ploshchad station and heading to the Technology Institute station, Russia's National Anti-Terrorist Committee said.
Russian security agencies found and defused a second explosive device at the Ploschad Vosstaniya station, one of the city's busiest stations, the committee also said.
Polina, who was travelling in the next carriage, told Bumaga when the train pulled into the Technology Institute station she "saw that the neighbouring carriage was mangled, window glass was broken, there was no light and there was blood."
Russia's health minister, Veronika Skvortsova, said seven people were killed immediately while another died in an ambulance and two more died in hospital. The death toll was later updated from 10 to 11.
