Volgograd blasts: Bus explosion hits Russian city
30 December 2013 Last updated at 06:39 GMT
At least 14 people have been killed, including a one-year-old child, and 23 others hurt in a suspected suicide bombing on a trolleybus in the Russian city of Volgograd, officials say.
It comes a day after 17 people died in another suicide attack at the central station and is the third blast in the city in two months.
Daniel Sandford reports that there are fears that militant groups could be ramping up violence in the run-up to the 2014 winter Olympic Games in the city of Sochi.