Police experts examine the remains of the car of the Islamic leader of Russia's main Muslim region of Tatarstan, following a car blast in Kazan on July 19, 2012. (Roman Kruchinin/AFP/Getty Images)

Investigators arrested five suspects Friday in the attacks a day earlier on Muslim leaders in the Volga River city of Kazan. The two victims — one was injured and the other killed — were prominent defenders of traditionalist Islam against the encroachment of younger, radical imams who espouse a strict Salafi interpretation of the faith.

One of the suspects is the head of a company that arranges travel for the hajj, or Muslim pilgrimage to Mecca. Police said there had been a dispute about the company between him and men who were attacked, but suggested the conflict was as much ideological as commercial.

Kazan is the capital of Tatarstan, the traditional heartland of Russia’s Muslim population. The mufti, or Muslim leader, of Tatarstan, Ildus Faizov, remained hospitalized Friday after his car was destroyed by a bomb Thursday morning.

Valiulla Yakupov, a deputy mufti who was the ideological leader of the traditionalists, had been shot dead about an hour earlier.