Police have killed a senior Islamist militant in a shootout in Russia's North Caucasus ahead of the Winter Olympics in Sochi, the National Anti-terror Committee said on Tuesday.

The shooting of Eldar Magatov, a suspect in numerous attacks on Russian targets, at a house where he had taken refuge in the Dagestan region was part of an intensifying security clampdown as the Games approach.

President Vladimir Putin has staked his political reputation on organising a successful Olympics and tightened security nationwide after insurgents who hope to create an Islamist state in the North Caucasus threatened to attack the Games.

Magatov led an insurgent group in the Babyurt district of Dagestan, the National Anti-Terror Committee said. Dagestan has become the focal point of the insurgency, which is rooted in two separatist wars in neighbouring Chechnya.

In a video published on Monday, two men said by an Islamist militant group to have carried out twin suicide bombings in the southern city of Volgograd last month warned Putin to expect more attacks if the Games go ahead in Sochi.

The attacks in Volgograd killed at least 34 people and raised security fears before the Olympics, which open on Feb. 7 in Sochi, a Black Sea resort on the western edge of the Caucasus mountains.

In Sochi itself, residents say posters have appeared of a woman from Dagestan whom the Russian authorities suspect could be planning a suicide bombing. Putin has said Russia can cope with the security threat.

(For more sports news and updates, follow Ahram Online Sports on Twitter at @AO_Sports and on Facebook at AhramOnlineSports.)