The derailment of a train traveling from the Chechen capital Grozny to Moscow on Sunday was apparently caused by an explosion on the tracks, the Federal Security Service said. Twelve people were injured. An FSB spokeswoman said the train's driver reported that an explosion occurred on the tracks in front of the train. The spokeswoman also said a crater and wires were found at the site, 150 kilometers (90 miles) south of Moscow.