MOSCOW (Reuters) - A gunman and a police officer were killed on Sunday during an attack on a road checkpoint in Russia s volatile Caucasus region of Ingushetia, TASS news agency reported, citing security services and a medical source.  One bandit was neutralised, another was blocked in a building during a shootout at a police road checkpoint near the village of Yandare,  TASS reported citing a statement from the National Anti-Terrorist Committee (NAK). Three injured road police officers were rushed to hospital, TASS said, citing a medical source. Throughout the 18 years since Vladimir Putin rose to power and crushed a Chechen separatist revolt, Russia has battled an insurgency seeking to carve an Islamic state out of the provinces of Chechnya, Ingushetia and Dagestan. 