LONDON: More than 11,000 children have died in Syria’s civil war, including 128 killed by chemical weapons in a notorious attack and hundreds targeted by snipers, a British think-tank said Sunday.

The Oxford Research Group, which specializes in global security, said in a new study that there were 11,420 recorded deaths of children aged 17 years and under.

The report, entitled “Stolen Futures: The hidden toll of child casualties in Syria,” analyzes data from the beginning of the conflict in March 2011 until August 2013.

The think-tank added that, of the 10,586 children whose cause of death was recorded, 128 were killed by chemical weapons in Ghouta, near Damascus, on Aug. 21,2013, in an attack that the United States and other world powers blamed on President Bashar Assad’s regime.

The think-tank added on Sunday that 764 children were summarily executed and 389 were killed by sniper fire in the conflict. Explosive weapons have caused more than 70 percent of the child deaths, while small arms fire accounts for more than a quarter, according to the study.