Just a day after a female suicide bomber was blamed for killing 17 people and leaving dozens more injured in the Russian city of Volgograd at least 10 people have reportedly been killed after a bomb blast ripped through a trolleybus.
Investigators have described the blast as "an act of terror".
Now, a horrifying video has emerged of the moment the first attack was carried out.
The CCTV footage broadcast by news station Rossiya 24 showed the devastating affect of the blast at the railway station in Volgograd.
Police have identified the first bomber as a Dagestan national called Oksana Aslanova - who had been married to two Islamists killed by Russian forces.
She apparently detonated a bomb in front of a metal detector inside the main entrance of the station. Russian television is suggesting there may have been two attackers.