Details added (first version posted at 09:27)
A terrorist attack in the Russian city of Volgograd has killed at least 15 passengers on a trolley bus. The explosion comes a day after a suicide bombing in the city which killed 17 people and injured scores of others, Russia Today reported.
At least 23 people were injured by the blast on Monday morning, according to Volgograd region Vice-Governor Vasily Galushkin.
Earlier police reported at least 10 fatalities and at least 15 injured in the blast.
A one-year-old baby is reported to be among the victims.
The explosion was set off by a suicide bomber, spokesman for the Russian Investigative Committee, Vladimir Markin, confirmed.
The bomb may have been planted in the central part of the trolley bus rather than brought in by a suicide bomber, said the National Antiterrorist Committee.
The bus was near one of the city markets when the explosion happened. The site has been cordoned off, with traffic diverted to other streets.
The blast wave was powerful enough to shatter some windows in nearby buildings.