Saudi Arabia
Saudi ArabiaReuters

The Grand Mufti of Saudi Arabia exacerbated already serious tensions with Iran when he claimed that the leaders of the Shi'ite country aren't Muslims yesterday (Tuesday).

Abd al-Aziz Al ash-Sheikh, the foremost religious leader of Saudi Arabia, made the comments a day after Iranian supreme leader Ayatollah Ali Khamenei accused Saudi authorities of killing injured Muslims during the Hajj tragedy in Mecca last year, in which at least 2,426 people lost their lives in a stampede while visiting Islam's holiest site.

Khamenei's comments were published on his official website on Monday, with the Ayatollah saying that "the heartless Saudi murderers trapped the injured together with the dead, and refused to give them medical treatment or even just a drink of water. They murdered them."

Tensions between the two countries have been running high due to longstanding religious differences (Iran is Shi'ite and Saudi Arabia Sunni), and regional political conflicts, as the countries have supported opposing sides in the civil wars in Syria and Yemen.

In response to Khamenei's words, the Saudi Grand Mufti told the Mecca newspaper in an interview that the Iranian leader's comments were "not surprising," as the Iranians are the descendents of the Zoroastrians, a religious group that had assimilated elements of Islam and Christianity before being conquered by the Arabs. "We must understand that they are not Muslims, as they are the descendents of the Magus, and their animosity towards Muslims - especially the Sunnis - is very ancient," Al ash-Sheikh said.

The death toll from the Hajj tragedy last September showed that Iran had the highest number of casualties, with 464 of its citizens dead. The official Saudi position has a far lower death toll and they haven't published an assessment of the cause of the disaster. Stampeding by massive numbers of people fulfilling the commandment to make the pilgrimage to Mecca (one of the pillars of Islam) has been tabbed as the likely cause.

Khamenei has blamed the Saudis for the tragedy and urged Muslims throughout the world to challenge the status quo in which Saudi Arabia controls the holy sites in Mecca and Medina. He claims that the Saudis foster religious divisions and arm "the evil infidel groups," referring to extreme Sunni organizations like ISIS, who see the Shi'ites and any other Muslim minority group as infidels deserving death.

Negotiations between the two countries regarding security arrangements for the annual Hajj collapsed in May, leading Iran to declare that it will not send its citizens on the pilgrimage that begins at the end of this week.