Egyptian religious leader Sheikh Mohammed Sayyed Tantawi, the grand sheikh of al-Azhar, has died of a heart attack during a visit to Saudi Arabia, Egypt's official MENA news agency reported on Wednesday. 

Tantawi, 81, was in Riyadh to attend the King Faisal awards ceremony, it said. Tantawi's moderate views has rankled hard-liners. 

The news of his death was "an indescribable shock," his son Amr Tantawi told Egyptian television.

"The family has decided that since God chose for him to die on Saudi land, he will be buried in al-Baqie" cemetery in Islam's second holy city of Medina, his son added. 

Tantawi was apponted as the Grand Imam of al-Azhar since 1996. Al-Azhar, one of the most prominent seats of Sunni Islamic learning in the Muslim world, has schools, universities and other educational institutions across Egypt. 

Abdullah el-Naggar, advisor to the sheikh, told Egypt's Nile News television the death was a surprise, saying that before leaving to Saudi Arabia the sheikh had seemed in "excellent shape and health." 

A member of Tantawi's office, Ashraf Hassan, told Reuters that Mohammed Wasel, Tantawi's deputy, was expected to temporarily take over leading the institution until the Egyptian president appointed a new head for the body.

Most recently, Tantawi infuriated conservatives late last year by barring women from wearing the full face veil known as the 'niqab' at al-Azhar University. That step was part of the intensifying struggle between the moderate Islam championed by the state and a populace that is turning to a stricter version of the faith. 

Al-Azhar receives most of its funding from the state.

When he was appointed, Tantawi was viewed as having relatively liberal views on issues such as women's rights but had been criticized by some for toeing the government's line. 

In office, he opposed female circumcision as not an Islamic practice.

Al Arabiya