He was recovering from cancer, however, the exact cause of his death is unknown.[36][37][38] A military funeral was held for Zewail on August 7, 2016, at the El-Mosheer Tantawy mosque in Cairo, Egypt.[38] Those attending included President Abdel Fattah el-Sisi, Prime Minister Sherif Ismail, al-Azhar Grand Imam Ahmed el-Tayeb, Defence Minister Sedki Sobhi, former President Adly Mansour, former Prime Minister Ibrahim Mahlab and heart surgeon Magdi Yacoub.[38] The funeral prayers were led by Ali Gomaa, former Grand Mufti of Egypt.[38]