MOSCOW — President Vladimir Putin ordered Russia's security services to be on high alert on Thursday to protect against attacks by Islamist militants in the run up to next year's Winter Olympics in the Black Sea resort city of Sochi.

Putin, speaking after a suicide bomber killed three policeman in a Caucasus province across the mountain range from the Sochi region, said "all anti-terrorist forces should be at the highest level of alertness and readiness."

"The most important thing here is the protection of people's lives. It is necessary to provide reliable anti-terrorist protection of... large-scale public, international events soon to take place in our country," Putin told senior officials from the Federal Security Service.

Russia fought two wars against separatists in its Chechnya province following the collapse of the Soviet Union, a conflict that has slowly turned into an insurgency that aims to carve out an Islamic state in the Caucasus.

Sochi, host of the 2014 Winter Games, is at the western end of the Caucasus Mountain range.