A female suicide bomber set a bomb off at the entrance of a Moscow train station on Sunday, killing between 13 and 18 people. The explosion occurred around 12:45 pm.

This is the second deadly bombing to occur in Moscow in two months, according to RIA Novosti. While between 13 and 18 were killed, over 50 were wounded by the bombing.

This has certainly heightened the concern of terrorist attacks during the upcoming Sochi games, according to the LA Times. The government has sent out thousands of soldiers and policeman to make sure that the Olympic games will be safe.

In October something quite similar occurred in Moscow when another female suicide bomber set a bomb off in a city bus. This bombing killed six and injured approximately 30 people.

More recently, Friday three people were killed after a car filled with explosives was set off. These are just a few of multiple bombings that have taken place in the past few years. Moscow and Russia have had a chain of terrorist attacks.

Rebel leader Doku Umarov who had claimed responsibility for bombings in 2010 and 2011 has called on his fellow rebel men and women to “do their utmost to derail” the Sochi games.