ON-DON, Russia, December 09 , SPA -- An explosion on a bus Sunday killed two people and wounded four others in southern Russia, officials said, according to AP. The blast occurred when a bus traveling from Pyatigorsk to Stavropol stopped in the city of Nevinnomysk, said Sergei Kozhemyaka, a spokesman for the Emergency Situations Ministry's branch in southern Russia. Kozhemyaka said the explosion in the back of the bus killed two passengers and wounded another four. It wasn't immediately clear what caused the blast. Russia's southern provinces have remained restive, plagued by frequent explosions and other violence, some of which was spilling from Chechnya and other attributed to local criminal clans.
