A suicide bomber on a bus in Volgograd, Russia killed at least 14 people on Monday.

This is the second suicide bombing in only 24 hours, which brings concern, once again, about the Sochi Olympic Games. This second bombing killed at least 14 people and injured 30. That makes 31 deaths from suicide bombings in just 24 hours.

According to USA Today,Vladimir Markin, the spokesman for Russia’s investigative agency said that the bomb used in Monday morning’s incident was very similar to the bomb used on Sunday. Investigators believe that the two bombings were linked.

According to RIA Novosti, Markin said that the suspect bombers have been recovered from the debris and are currently undergoing DNA testing to recover their identities.

Doku Omarov, leader of the rebel terrorist Group called the Caucasus Emirate, is calling upon the people of Russia, as well as Muslims to disrupt the Sochi Olympics.

President Vladimir Putin has called for an increase in security across the country after these two fatal attacks.

Families of each person that was killed in the bombings in the past 24 hours will received 1 million rubles ($305,000) and each families of the injured will receive between 200,000 and 400,000 rubles ($6,000-$12,200).

In the past decade there have been approximately 20 terrorist bombings, claiming 780 lives.