Two explosions on the Moscow Metro on the morning of 29 March killed at least 37 people after two female suicide bombers blew themselves up.
A further 33 people were injured following the incidents, the first at just before 8am local time with the second explosion 40 minutes later.
The first blast took place at Lubyanka station, near the Russian Federal Security Service headquarters, killing 26 people on the train and platform.
The second attack at Park Kultury station claimed the lives of another 12 people.
So far no group has claimed responsibility for the attack, with suspicions falling on Islamic rebels from the North Caucasus region of Chechnya.
The Moscow Metro carries 5.5 million passengers a day on its 278km track, featuring 11 interconnected lines, making it one of the busiest underground systems in the world.