Two police officers were killed and two others were wounded late on Thursday in an attack on a police car in Nazran, the largest city in Russia's North Caucasus republic of Ingushetia, a local police source said.
"Approximately at 10.30 pm Moscow time [20:30 GMT] a group of unidentified gunmen opened fire at a police patrol car carrying four police officers in the center of Nazran," the source said.
"As a result, two police officers were killed and another two were severely injured," he said.
Police have launched a search for the assailants, the official said.
More than a decade after the end of a war against separatists in Russia's North Caucasus republic of Chechnya, Russian security forces continue to fight militants in other regions in the area besides Chechnya, including Kabardino-Balkaria, Ingushetia, Dagestan, and North Ossetia.
Frequent attacks are staged on security forces, police and civilians.
