Iranian President Mahmoud Ahmadinejad is in Egypt for a two-day summit of the Organization of Islamic Conference that began Wednesday in Cairo.
His arrival marked the first visit to Egypt by Iranian officials since the 1979 Islamic Revolution.
Iran cut diplomatic ties with Egypt in 1980, following the signing of the Israeli-Egyptian peace treaty in 1979. Those ties remained severed until the overthrow of former President Hosni Mubarak's regime in January 2011.
Egyptian President Mohammed Morsi welcomed Ahmadinejad and his delegation as they deplaned, greeting the Iranian leader with a kiss on each cheek, aired on Egypt's state TV.
But some of Egypt's Sunni Muslims weren't happy about the visit.
Ahmadinejad received a less effusive welcome from Ahmed el-Tayyeb, Egypt's most prominent Sunni cleric, at al-Azhar, Sunni Islam's renowned learning institution.
Tayyeb criticized Ahmadinejad's interference in the affairs of Sunni nations, such as Bahrain, and warned him against trying to "spread Shiaism in Sunni lands."
"The Iranian president [should] respect Bahrain as a brotherly Arab nation and not interfere in the affairs of Gulf States," Agence France Presse quoted Tayyeb as saying.
Later outside Cairo's al-Hussein mosque, a Syrian exile hurled a shoe at Ahmadinejad, the ultimate insult in the Islamic world, shouting at him that he'd "ruined Syria."
Others spat at his motorcade as it passed by. Ahmadinejad and Iran's other Shiite leaders have been unflinching supporters of Syrian President Bashar Assad.
On Monday evening, Ahmadinejad said he would like to "go to Gaza to visit the people" and plans to "pray in Jerusalem after complete liberation," Reuters reported.
Last summer, Morsi met with Ahmadinejad on the sidelines of the U.N.-sponsored Non-Aligned Movement conference in Tehran.