RIYADH – Saudi Arabia’s top cleric escalated the kingdom’s rivalry against Iran, saying in comments published on Tuesday that Tehran’s leaders are “not Muslims” in response to harsh remarks from Iran’s supreme leader.

“We must understand these are not Muslims, they are children of Magi and their hostility towards Muslims is an old one. Especially with the people of Sunna,” Grand Mufti Abdulaziz al-Sheikh said in comments to the Makkah newspaper, adding that Khamenei’s remarks did not surprise him. The term “Magi” refers to Zoroastrianism – a monotheistic religion older than Islam that was once dominant in Persian lands before the Arab conquest.

The grand mufti’s comments came a day after Iran’s Ayatollah Ali Khamenei said the Muslim world should challenge Saudi management of Islam’s two holiest sites in Makkah and Madina.

The verbal sparring, ahead of the Hajj which this year starts on Saturday, follows months of tension between Sunni-dominated Saudi Arabia and its Shia regional rival Iran.