MOSCOW — A suicide bombing at a railroad station in Volgograd in southwestern Russia killed at least 15 other people on Sunday, officials said, raising the specter of a new wave of terrorism ahead of the Winter Olympics in Sochi in February.
Scores of people were wounded, some of them critically, which means the death toll could rise.
The explosion, which officials said was caused by a bomb possibly carried in a bag or backpack, struck the main railroad station in Volgograd, a city about 550 miles south of Moscow, at 12:45 p.m.
There was no immediate claim of responsibility, but Volgograd borders the restive Caucasus region. Chechen rebel leader Doku Umarov called several months ago for attacks against civilian targets in Russia. Full story for BostonGlobe.com subscribers.