 Responsibility for the attack was immediately pointed at Chechen terrorists, who had committed previous attacks on trains on the line shortly before, including one on September 3, 2003, killing 7 and injuring more than 80.Ibragim Israpilov, a former local official from Chechnya, was convicted in 2004 for organizing the September blast and sentenced to 20 years of imprisonment.He is sometimes erroneously reported as being behind the December 5 bombing.