A bomb exploded in a busy pedestrian tunnel beneath Pushkin Square in Moscow Aug. 8, and the next day another bomb was found in Kazansky railway station. Seven were killed and scores were injured in the explosion, which was being blamed on Chechen rebels who were implicated in the bombing of an apartment building a year ago. If it was the act of terrorists, it could signal a new wave of violence in Moscow. No proof has yet been found, however, and it’s possible the incident was perpetrated by gangsters attacking their enemies in a turf war.