Russian authorities say three law enforcement officers were killed in two separate incidents in the southern Daghestan region on August 28, including an attack claimed by the Islamic State (IS) group's propaganda agency.
Russia's National Antiterrorism Committee said in a statement that two officers and two suspected militants were killed in a shoot-out on the outskirts of the town of Khasavyurt in the North Caucasus republic.
The deadly clash erupted after the suspects refused to surrender, the committee said.
Meanwhile, regional investigators in Daghestan said that on the morning of August 28, one local police officer was killed and another injured in a knife attack by two assailants in the town of Kaspiisk.
Investigators said in a statement that the two assailants were killed by police following the attack.
There was no mention of terrorism in the statement, but the IS propaganda agency Amaq later called the attackers "soldiers of the Islamic State."
The head of Daghestan's regional security council, Abdulmuslim Abdulmuslimov, was quoted by the Russian business daily RBK as downplaying claims of IS involvement. He said the claims were "untrue" and aimed at "destabilizing the situation in the republic," RBK reported.
The state-run TASS news agency cited an unidentified source as saying that authorities recovered two knives and IS paraphernalia.
Daghestan and other mainly Muslim republics in the North Caucasus are the site of frequent fighting between government forces and militants whose insurgency stems from two post-Soviet separatist wars in Chechnya.
Russia says hundreds of its citizens, mainly from the North Caucasus, have fought alongside Islamic militants in Iraq and Syria.
The IS-affiliated Amaq also claimed responsibility for an August 19 stabbing rampage in the Russian city of Surgut that left seven people injured.
The attacker, a local Surgut resident, was shot dead by police following the attack.