moscow gunman police officer kill sunday attack road checkpoint russia volatile caucasus region ingushetia tass news agency report cite security service medical source one bandit neutralise another block build shootout police road checkpoint near village yandare tass report cite statement national anti-terrorist committee nak three injure road police officer rush hospital tass say cite medical source throughout 18 years since vladimir putin rise power crush chechen separatist revolt russia battle insurgency seek carve islamic state provinces chechnya ingushetia dagestan gunman police officer kill russian road checkpoint attack tass