Three clerics were stabbed by an unknown attacker at a religious shrine in the northeastern Iranian city of Mashhad, killing two, media reported on April 5.
The semiofficial Tasnim news agency said one of the clerics had died following the attack. Tasnim identified him as Mohammad Aslani. Meanwhile, the semiofficial Mehr news agency said a second clergyman, identified as Mohsen Pakdaman, had died after being taken to a hospital.
Astan Quds Razavi, the foundation that runs the shrine of Imam Reza, said the alleged attacker was immediately detained and taken into police custody. The motive of the attack is unclear.
"The identity of the assailant is under investigation," Astan Quds Razavi said in a statement.
The organization said it will release further details about the attack later.
Mashhad’s Prosecutor's Office said five people had been detained over the stabbing: the attacker and four other individuals who accompanied him.
A video posted online by Iranian media showed a man lying in a pool of blood in the courtyard of the shrine.
Another video appeared to show security forces and pilgrims detaining the alleged assailant.
The Imam Reza shrine is visited by millions of pilgrims every year.
The attack came two days after the start of the Muslim fasting month of Ramadan in Iran.
It follows an April 3 incident in a mosque in the northern town of Gonbad Kavus during which two Sunni clerics were shot to death. Authorities said one suspect was arrested and that, based on evidence, “personal motives" were behind the attack.