MOSCOW, August 17 - RAPSI. Seven suspects in the notorious case of the assassination attempt of religious leader, Tatarstani mufti, Ildus Fayzov, and the murder of the head of the Spiritual Muslim Board of Tatarstan, Valiulla Yakupov, were released.

The investigative process with respect to these suspects has been completed for now and they were released, the Investigative Committee report says.

Only one suspect remains in custody.

On July 19, a car exploded in Kazan injuring Tatarstan mufti , Ildus Fayzov. On the same day, the head of the Spiritual Muslim Board of Tatarstan, Valiulla Yakupov, was shot dead near his home. Both religious leaders were known for their crusade against extremism.

Tatarstan authorities announced a one million ruble ($31,390) reward for information leading to the arrest of three alleged terrorists suspected in the assassination attempt of Fayzov and the murder of Yakupov.

The two investigations, one into the murder and one into the attempted murder, have been combined into a single case. Additionally, investigators qualified the attempted assassination as an act of terror.

"Radical Islamists Rais Mingaleyev, Robert Valeyev and Albert Ismagiolov are being sought under suspicion of organizing serious crimes including murder and acts of terror," the statement reads.