A bomb exploded in a shop in an Ingush town on Friday, killing two police officers investigating the shooting of the shopkeeper there earlier in the day, Interfax reported.
The blast was the most deadly of a series of attacks in Ingushetia and Dagestan on Friday that killed five people and injured more than a dozen others.
The bomb went off as police and local officials gathered at the store in Sagopshi to investigate the shooting of the shopkeeper by an unidentified gunman. The blast, which had the force of five kilograms of dynamite, killed a policeman and injured 16 other people, including the town mayor and his deputy, Interfax said. A second police officer died later of his injuries.
The shop was totally destroyed.
In the neighboring town of Malgobek, a gunman attacked a group of police officers and explosives experts called after residents discovered two explosive devices next to a World War II monument. The attacker was killed in the ensuing gunfight.
The explosives went off during the attempt to defuse them. No one was injured.
In two separate attacks in Dagestan, a Muslim cleric and a local official were killed.
Imam Magomed Kazakbiyev died after unidentified gunmen opened fire on worshippers on their way to a mosque in the outskirts of Makhachkala, the regional capital, Interfax reported. Kazakbiyev headed a local group of dissenting Muslims who are not recognized by the region's official Islam or by the radical Wahhabis who have been blamed for much of the region's violence.
Unidentified gunmen also shot dead Asadi Shikhbabayev, head of the Magaramkent administration just outside the southern Dagestani city of Derbent. Shikhbabayev's predecessor was gunned down in Makhachkala last November, the report said.