One Iranian cleric was stabbed to death and two others were injured on Tuesday in a rare attack at Iran’s largest holy Shia Muslim religious complex in the north -eastern city of Mashhad, Iranian state media reported, and Reuters reports.

Iran’s semi-official Tasnim news agency said the assailant had been arrested and the injured clerics were transferred to the hospital after being stabbed with a knife in the courtyard of the Imam Reza shrine on the third day of the Muslim fasting month of Ramadan.

Videos posted on social media, which could not be authenticated by Reuters, showed two men on the ground of the shrine’s courtyard, covered with blood. Iran’s state news agency, IRNA, posted footage of police arresting the assailant, without identifying him.

State television identified the cleric who was killed as Mohammad Aslani, but gave no details about the injured ones and their conditions.

“The identity of the arrested assailant is under investigation,” state TV quoted a statement by the Astan Qods Razavi, a multi-billion-dollar religious conglomerate, which manages the shrine.

In 1994, a bomb ripped through the main hall at the Imam Reza shrine, killing 26 people.

On Sunday, Iranian media reported the killing of two Sunni clerics in a mosque in the town of Gonbad-e Kavus in Iran’s northern Golestan province, without providing details.