A female suicide bomber posing as a Muslim pilgrim killed a leading moderate Islamic scholar and at least five others Tuesday in the restive southern Russian republic of Dagestan.

Dagestan's interior ministry says Said Atsayev, a widely respected Suffi Muslim spiritual leader who opposed radical Islam, was killed when the unidentified woman entered his home in disguise and detonated an explosives belt around her waist.

The Dagestan attack was reported as Russian President Vladimir Putin began delivering a keynote address related to a separate assassination attempt last month against another top moderate cleric in the republic of Tatarstan. It was not clear whether Mr. Putin knew of the Dagestan bombing as he began his address.

Elsewhere in Dagestan, a Russian border guard killed at least seven servicemen in a shooting spree at a border post Tuesday. The motivation for the attack is unknown, but authorities are quoted as saying they suspect the shooter also may have had ties to militant groups.

Moscow is struggling to contain an Islamic insurgency in its largely-Muslim North Caucasus region, nearly a decade after fighting two wars against separatists in Chechnya. Russia claims the region is largely under control, but sporadic bombings, assassinations and attacks on government facilities and troops continue.