On Monday, an explosion tore through a train carriage in a metro tunnel in the Russian city of St Petersburg, killing at least 14 and injuring 49.
Kyrgyzstan security services said Tuesday the attack was staged by a "suicide bomber" named Akbarjon Djalilov, a naturalised Russian citizen born in southern Kyrgyzstan in 1995.
This was the first major attack in Russia since 2013. Here is a list of similar incidents.
December 29, 2013
A suicide bomber hit the main train station in Volgograd, the southwestern city formerly known as Stalingrad. The blast heightened security fears six weeks before Russia hosted the Winter Olympic Games in Sochi. Sixteen people were killed and at least 50 were inured.
The next day, another suicide bomber targeted a packed trolleybus in the same city killing 14.
President Vladimir Putin put the army on high alert, and the Olympics took place without major incident. The Caucasus Emirate group, a Chechen militant group claimed responsibility.
October 21, 2013
A suicide bomber attacked a bus packed with students in Volgograd, killing six. The bomber was from the volatile North Caucasus region of Dagestan.
January 24, 2011
In January, a bomb ripped through the arrivals hall at the Moscow’s Domodedovo International Airport, killing 37 and injuring more than 100. The suicide bomb was linked to the Caucasus Emirates.
March 29, 2010
Twin bombs struck two metro stations in central Moscow within 40 minutes of each other during morning rush hour. The blasts killed 40 people and injured 60. The Caucasus Emirate group claimed responsibility.
November 27, 2009
A bomb in a high speed passenger train running from Moscow to Saint Petersburg killed 28 people and derailed the train. Chechen militants claimed responsibility. A special forces operation eventually killed Sheikh Said Buryatsky who was alleged to be behind the bombing along with his associates.
September 1, 2004
More than 300 people were killed when over a dozen militants entered a school in Beslan in North Ossetia. The siege, in which 1,200 people were taken hostage, lasted more than a day. It ended when the Russian army stormed the school. The militants were reported to be connected to a Chechen warlord, Shamil Basayev who was killed two years later.
February 6, 2004
A bomb blast at a packed subway in the Moscow capital during the morning rush hour killed 41 people.