Police said one police officer has been killed and two wounded in Russia's Daghestan region in an attack claimed by the Islamic State extremist group.
"Two cars were blown up. The type of explosive device has not been established yet," Fatina Ubaidatova, a spokeswoman for the Daghestani police, told Reuters by phone.
The Amaq news agency, which supports IS, posted a statement online saying its local affiliate was behind the attack late on March 29.
Islamic State has in the past said it was behind violent attacks on security forces in the North Caucasus, the volatile mainly Muslim part of Russia where Daghestan is located.
Daghestan, where Kremlin critics say widespread poverty and corruption help feed religious extremism, last saw similar attacks on police in February.
Some militants in Daghestan, which borders Chechnya where Moscow led two wars against separatists in 1990s, have sworn allegiance to Islamic State.