A group of militants attacked a police checkpoint in Russia’s North Caucasus region, killing two officers, officials said Monday.

Four other officers were wounded and all five attackers were killed in the shootout in the Karachay-Cherkessia region late Sunday, according to the regional branch of Russia‘s Interior Ministry.

The Investigative Committee, the country’s top state criminal investigation agency, said the same gunmen had raided another police checkpoint in the region a week before, killing two police and injuring another. It didn’t describe the attackers’ affiliation or motive.

While Chechnya has stabilized under the rule of Moscow-backed leader Ramzan Kadyrov after two separatist wars, violence linked to Islamist groups has occasionally erupted in other parts of Russia‘s volatile North Caucasus.

The Karachay-Cherkessia region in particular has experienced a series of raids on police by extremists.

In December, Russia‘s Federal Security Service, the nation’s top domestic security and counter-terrorism agency, reported the arrest of 14 suspected members of a radical Islamist group in Karachay-Cherkessia. It followed earlier arrests of other suspected members of the same group in the region.