DUBAI (Reuters) - Egyptian religious leader Sheikh Mohamed Sayed Tantawi, the head of al Azhar, has died on a visit to Saudi Arabia, Al Jazeera television reported on Wednesday, quoting its correspondent. 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. Cairo - Sheikh Mohamed Sayed Tantawi, the head of Egypt's most prestigious seat of Islamic learning al-Azhar, died of a heart attack on Wednesday during a visit to Saudi Arabia, religious officials at al-Azhar said. He was 81. 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 Mohamed Wasel, Tantawi's deputy, was expected to temporarily take over leading the institution until the Egyptian ...