A suicide bombing on a Russian commuter train near Chechnya killed at least 40 people and wounded 150 others on Friday. Russian President Vladimir Putin said the attack was an effort to disrupt the weekend's parliamentary elections.

A tense security situation continues to dog the Russian republic of Chechnya, despite efforts by Moscow to reduce the federal forces patrolling the war-torn region and encourage Chechens who have fled the country to return to their homeland.