Since the civil war began in 2011, Assad's regime launched 98 percent of such attacks, a German-based institute reports.
The Assad regime carried out the majority of over 330 reported chemical attacks in Syria over the last eight years, according to a German-based think tank.
In a report titled "Nowhere to Hide: The Logic of Chemical Weapons Use in Syria", Berlin-based Global Public Policy Institute (GPPI) said on Sunday that some 336 chemical attacks were recorded in Syria since the start of the civil war.
Nearly 98 percent of the attacks were carried out by the regime forces, the report added.
Since the Khan Shaykun attack
Daesh, meanwhile, conducted six of the chemical attacks in the war-torn country.
The report said that approximately 90 percent of the attacks occurred after the August 2013 chemical attack killed hundreds of people in the suburbs of the Syrian capital Damascus. Then-president Barack Obama had called such attacks a “red line".
During the first three years of the conflict, Washington's Syria policy was based on Obama's demand that Syrian regime leader Bashar al Assad step down; economic sanctions imposed on the regime; and frequent warnings against crossing the “red lines”.
Syria has been locked in a vicious war since early 2011, when the Assad regime cracked down on protesters with unexpected ferocity.
Since then, hundreds of thousands of people are believed to have been killed and millions more displaced by the conflict.