Ten people have been killed in a blast on a trolleybus in the southern Russian city of Volgograd, a day after a suicide bombing at the city's main train station, according to officials.
"According to initial information, 10 people were killed and 10 were wounded," the spokeswoman of the local branch of the emergencies ministry, Irina Gogolev,a told the Interfax news agency.
Reports said that the explosion was so strong that the trolleybus, a common form of municipal transport in Russian cities, was completely destroyed.
Russian news agencies quoted unnamed local officials as saying that the blast was likely to have been an attack. "This is another act of terror, this time in a trolleybus," a investigative source told RIA Novosti.
Another source told the ITAR-TASS news agency that the blast could have been caused by a suicide bomber.
A suicide bomber killed at least 15 people, plus herself, on Sunday in the attack on the train station of Volgograd, heightening security fears six weeks before the Winter Olympics in Sochi.
