The Islamic State (IS) militant group on Thursday claimed the killing of two traffic police in southern Russia this week, as security agencies said they had shot dead four suspects.
The Amaq propaganda agency linked to IS reported the killing of "two Russian policemen" in the southern city of Astrakhan, citing a "security source".
It also claimed an attack that wounded three National Guard officers on Thursday in an incident Russian authorities said saw one assailant suspected of involvement in the death of the traffic policemen shot dead.
The interior ministry said the suspect was killed after opening fire when the car he was travelling in was stopped by law enforcement officers.
Three more suspects were later "liquidated" during a security operation in the city, the ministry said.
Local authorities had previously called the killing of the two traffic policemen a "brazen attack" by "radical Islamists".
The IS claim comes with Russia on high alert following a bombing on the Saint Petersburg metro on Monday that killed 13 people.
There is no apparent link between the two attacks.
Russia's Investigative Committee has said it is looking for any possible connections between the alleged Saint Petersburg metro bomber and IS, but so far no one has claimed responsibility for the attack.
IS -- including foreign fighters from the ex-Soviet Central Asia and the Caucasus region -- have repeatedly threatened an attack on Russian soil to avenge Moscow's military backing of Syrian leader Bashar al-Assad.
Astrakhan lies several hundred kilometres (miles) northeast of the volatile North Caucasus, where Moscow is fighting a lingering Islamist insurgency.
While attacks against police regularly occur in Russia's Caucasus, they are much rarer in other regions.
