Gunmen killed two officers of Russia"s domestic FSB security service and wounded one in Russia"s Ingushetia province on Thursday, prosecutors said, according to Reuters. A suicide bomber blew himself up at a nearby police station several hours earlier, killing himself and wounding 23, including three children, media reported. The escalating violence across the largely Muslim North Caucasus led the Kremlin last month to call the region its biggest domestic problem. The heart of the violence is in Ingushetia, where political analysts say Islamist fighters and law enforcement officers are effectively at war. Gunmen riding in a black car shot at a vehicle carrying three FSB men in Nazran on Thursday afternoon, an Ingush prosecutor told Reuters in the region"s main city. "One of those attacked died on the spot, another died of his wounds on his way to hospital. The third one is wounded but is in stable condition," he said on condition of anonymity. A police official, who also declined to be named, confirmed media reports that a total of 23 people, some of them civilians, had been wounded in a suicide bomber attack at a road police post just outside Nazran earlier on Thursday. The car was the same black Lada Priora model as the gunmen in the later incident used but it was not immediately clear if it was the same car. "All transport vehicles were ordered to stop to let the column pass...then a Priora (Lada) with a Chechen license plate whizzed by and an explosion happened," Interfax news agency quoted Ingushetia"s prosecutor Yuri Turigin as saying. Kavkazcenter.com, a site which has links to the Islamist rebel movement, praised the suicide bomber, calling him a "martyr" who injured "infidels". Islamist militants say they want to create a Muslim, sharia-based state in the North Caucasus, separate from Russia. In August, a suicide bomber killed 25 people and wounded more than 100 at a police headquarters in Nazran, in the bloodiest attack to hit the North Caucasus since 2005. In neighbouring Chechnya, where Moscow has fought two wars against separatists since the mid-1990s, four men suspected of being Islamist fighters were killed by police earlier on Thursday, Interfax said, citing the Chechen Interior Ministry.