He was 122nd Patriarch of Antioch and All East.
The patriarch had visited India several times and had shown keen interest in the affairs of the Syrian Church in Kerala, an influential and oldest Christian denomination in the state.
A scholar in theology and oriental churches, he was born in Mosul in Iraq in 1933.
Zakka I was enthroned as Patriarch of the Syriac Church in September 1980, as successor to Ignatius Yaqub III. He had also served as Archbishop in Baghdad and Basra in Iraq.
Jacobite church in Kerala declared 40-day mourning and memorial prayers would be held in churches in the coming days, church sources said.