Security forces on Saturday killed two suspected militants who were holed up on a roof in the southern Russian city of Nalchik, police said.

In the latest violence in the tense Kabardino-Balkariya region, officers surrounded a five-story apartment building on the outskirts of the regional capital Nalchik where the suspected militants had taken refuge on the roof and opened fire in response to demands they surrender, Kabardino-Balkariya Interior Ministry spokeswoman Marina Kyasova said.

She said both gunmen were killed when security forces returned fire. State-run television showed footage of two bodies lying on a roof and reported that the owner of the apartment they had been staying in had been detained and questioned.

One of the gunmen was a native of war-ravaged Chechnya and was wanted on suspicion of attacks and abductions there, Kyasova said, and the other was a native of the Kostroma region northeast of Moscow who had identification documents issued in Ingushetia.

Chechnya, Ingushetia and Kabardino-Balkariya are all republics in Russia's ethnically mixed North Caucasus, where poverty and corruption, and persecution connected with Islam are fueling anger at the authorities. Deadly raids by security forces on homes inhabited by suspected militants are frequent.

Kabardino-Balkariya has been tense since October, when suspected Islamic extremists led a bold daylight attack on law enforcement and government offices in Nalchik that left at least 139 people dead, including 94 alleged attackers.

Relatives of alleged attackers say the assault was provoked by relentless official repression of innocent Muslims in the region. Since the attack, regional law enforcement have staged a wide-ranging investigation, and rights groups say innocent, observant Muslims have been swept up in the dragnet.