"Attempts to assassinate leaderships fighting Daesh (ISIL) do not serve the peace process and [efforts] to achieve a political solution in Syria,” Saudi Foreign Minister Adel al-Jubeir said on Tuesday.

Syria's General Command of the Army and Armed Forces, in a statement issued late on Christmas Day, confirmed that Zahran Alloush and several leaders of other Takfiri groups were killed in aerial attacks against terrorist hideouts in the Damascus countryside of Eastern Ghouta.

The General Command said the operation followed "a series of surveillance and monitoring operations, based on accurate intelligence."

According to the statement, many senior figures of "al-Rahman Legion" and "Ahrar al-Sham" terrorist groups were also killed in the attacks.

The Saudi foreign minister, whose country has been one of the staunch supporters of ISIL and other militant groups in Syria and neighboring Iraq, further criticized Moscow’s anti-terror aerial campaign in Syria, saying, "I don't know what the Russians have in mind," Press TV reported.

Moscow launched its air raids against ISIL and other terrorist groups in Syria on September 30, upon a request from the Syrian government.

The conflict in Syria, which flared in March 2011, has claimed the lives of more than 250,000 people and left over one million injured, according to the United Nations.

The world body says 12.2 million people, including more than 5.6 million children, remain in need of humanitarian assistance in Syria. The foreign-sponsored militancy has also displaced 7.6 million people.