The banned nerve agent sarin and chlorine were used in two more attacks in Syria last year, the global chemical-weapons watchdog has said.
The Organization for the Prohibition of Chemical Weapons (OPCW) said on June 13 that sarin was used south of the city of Ltamenah in the Hama area on March 24, 2017.
It also "concluded that chlorine was very likely used as a chemical weapon at Ltamenah hospital and the surrounding area" the following day.
The findings in Ltamenah were based on witness testimony, epidemiological analysis, and environmental samples, it said.
The OPCW did not assign blame for the attack. In March 2017, activists in the rebel-held area of Ltamenah accused the Syrian government of carrying out an air attack using chemical weapons against a hospital, a charge that Damascus denied.
Previous UN-OPCW investigations have found that Syrian government forces used both sarin and chlorine, while Syrian rebel forces once used sulphur mustard gas.
Days after the Ltamenah attacks, sarin was used in a deadly attack at nearby Khan Sheikhun, killing nearly 100 people. A UN-OPCW investigative team blamed that attack on Syrian government forces. Damascus denied responsibility.