A man blew himself up and two others were shot dead as they attacked a police station in southern Russia, local security forces said.
Two attackers were killed by officers as they tried to get into the police station in the town of Novoselitskoye in the Stavropol region, but a third succeeded in setting off an explosive device he was carrying, a spokesman for the local Interior ministry branch told ABC News.
Besides the attackers, no one else was hurt in the assault, the spokesman said.
Stavropol's governor announced the region was being put on a heightened alert following the attack, with extra security being deployed to schools and hospitals, Russian news agency Interfax reported.
Security forces had sealed off the area around the attack and were working to establish the attackers’ identities, Russia’s National Counter-terrorism Committee told Interfax.
No group immediately claimed responsibility for the attack but Stavropol neighbors Russia's restive North Caucasus region, where Russian security forces have been fighting a counter-insurgency against Islamic militants for around two decades. Novoselitskoye, where the attack took place, is located about 80 miles from the border with Kalbardino-Balkaria, a republic that regularly witnesses militant attacks on police.
Russia has been on especially high alert for terrorist attacks following its military intervention in Syria that began in September.
In November, a Russian passenger jet was blown up over Egypt by a bomb planted by an Islamic State affiliate. The Islamic State has pledged to carry out further attacks in Russia itself.