His crime: Preaching non-violence.

(Reuters) – A woman suicide bomber killed an influential Islamic cleric and six of his followers in Russia’s southern Dagestan region on Tuesday as President Vladimir Putin visited another mainly Muslim province and called for an end to religious violence.

Said Atsayev, 74, a popular Sufi Muslim spiritual leader also known as Sheikh Said Afandi al-Chirkavi, was killed when the woman entered his home disguised as a pilgrim and detonated an explosive belt around her waist, police sources said.

In a separate incident in another part of Dagestan, a border guard shot and killed seven other servicemen at a frontier post and was killed by return fire, the federal Investigative Committee said.

Interfax news agency quoted an unnamed law enforcement source as saying there were indications the gunman had been recruited by “bandits” – as authorities often refer to Islamic militants. The report could not be verified.

Russia is struggling to contain an Islamic insurgency in the North Caucasus more than a decade after federal forces toppled a separatist government in a war in Chechnya, adjacent to Dagestan. The violence threatens to spread to other mainly Muslim regions.

It was not clear whether Putin knew of the violence in Dagestan before he made his comments. Atsayev, killed in the suicide bombing, was popular among many in Dagestan, including in the government. Like the deputy mufti slain in Tatarstan, he was an opponent of militant Islam.

Thousands of people streamed to the Dagestani cleric’s funeral late on Tuesday and the regional leader declared a day of mourning on Wednesday.