Volgograd, Dec. 30- At least 10 people have been killed and more than 20 others hurt in a suspected suicide bombing on a trolleybus in the Russian city of Volgograd.
The blast comes a day after 17 people died in another suicide attack at the central station in the city.
Security has been tightened at railway stations and airports across Russia.
Moscow is concerned militant groups could be ramping up violence in the run-up to the 2014 winter Olympic Games in the city of Sochi.
The Olympic venue is close to Russia’s volatile north Caucasus region.
Volgograd lies about 900km (560 miles) south of Moscow, 650km north of the North Caucasus and 700km north-east of Sochi.
A spokesman for Russia’s Investigative Committee said both explosions were now being treated as acts of terrorism. (Source: BBC World)
