(CBS) - Two terrorists attacks in two days have left more than two dozen people dead in the Russian city of Volgograd.
This time, a blast on a trolleybus killed multiple people. This follows a suicide bombing at a train station in the city on Sunday. At least 16 people died in that attack. The bombings raise concerns about security in Russia during the upcoming Sochi Olympics in February.
Russian President Vladimir Putin has ordered tighter security at Russian airports and train stations.