At least 23 people were killed by an explosion late on 10 October in a regional police headquarters in Grozny. The dead included all of Chechnya's local police chiefs. Chechnya's Emergency Situations Minister Ruslan Avtaev said on 11 October that he is 100 percent certain the blast was caused by a bomb, not a natural-gas explosion. Chief Prosecutor Nikolai Kostyuchenko said the bomb must have been brought into the building by guerrillas who had infiltrated the local police force. (RFE/RL)