Military commander of Syria's Deir al-Zour operation against IS was killed in mine explosion Wednesday. (Xinhua Photo)

DAMASCUS, Oct. 18 (Xinhua) -- The main commander of the military operations against the Islamic State (IS) in Syria's eastern province of Deir al-Zour was killed by a mine explosion Wednesday, local media reported.

Issam Zahreddine, also known as Lion of the Republican Guard, was a Major General of the Syrian Republican Guard and was leading the military operations of the Syrian army against IS in Deir al-Zour.

The 56-year-old officer was killed on Wednesday when a landmine exploded in the Hwaijet Saqer area in the countryside of Deir al-Zour, where the Syrian army is advancing in the battles against IS.

During the three-year siege by IS on Deir al-Zour, Zahreddine, who is from the Druze minority in the southern province of Sweida, was the leader of the besieged Syrian forces inside the city.

Fighting alongside his son in Deir al-Zour during the siege, the officer sustained several injuries.

After the Syrian army broke the IS siege on Deir al-Zour last September, Zahreddine paid a visit to his family in Sweida, before returning to Deir al-Zour to complete his mission in fighting IS.