 A previously unknown Chechen terrorist group claimed responsibility for the bombing; the claim came from a group calling itself "Gazoton Murdash", and signed by Lom-Ali ("Ali the Lion").According to the statement, the group launched the attack to mark the fourth anniversary of the killing of scores of Chechen civilians by Russian soldiers in Grozny in the Novye Aldi massacre.Shamil Basayev said that for his organization, the cost was $7,000 U.S. dollars.