The world chemical weapons watchdog said Tuesday there were "no reasonable grounds" to prove Syria's allegations that poison gas was used against its soldiers in two incidents in 2017.
Damascus claimed seven Syrian troops were wounded in two mortar attacks involving chemical weapons during clashes with rebels in the village of Kharbit Massasneh, in the central province of Hama.
But investigators from the Organisation for the Prohibition of Chemical Weapons (OPCW) found there were "inconsistencies" and a lack of evidence to back up Syria's allegations.
They "concluded that there are no reasonable grounds to determine that chemicals were used as a weapon in the reported incidents," the Hague-based OPCW said in a statement.
Damascus had asked the watchdog to investigate what it called two "mortar attacks with poisonous gas" in July and August 2017 during a government offensive against the Free Syrian Army and Islamist rebels.
Syria said three soldiers were taken to hospital with symptoms including breathing difficulties, muscle spasms and frothing at the mouth, and alleged that the attack involved chlorine gas.
It said four casualties in the August incident suffered similar symptoms.
OPCW investigators made several trips to Syria during which they interviewed 18 people including casualties, and gathered evidence including photos and videos from the hospital, plus medical records.
But the watchdog said it "faced challenges in collecting sufficient information."
These included being unable to visit the front-line site of the alleged attacks, combined with the fact that Syria provided no photo or video evidence from the location, munition remnants or blood, clothing or soil samples.
Therefore investigators "cannot confidently provide a toxicological assessment of the reported exposure," the OPCW report said.
President Bashar al-Assad's regime has been blamed by the watchdog for a series of chemical attacks during Syria's civil war — including sarin and chlorine at Lataminah, near Kharbit Massasneh, in March 2017.
The OPCW found that the Islamic State group used mustard agent in a 2015 attack in northern Syria.
Damascus denies the use of chemical weapons and insists it has handed over its stockpiles under a 2013 agreement, prompted by a suspected sarin gas attack that killed 1,400 in the capital's suburb of Ghouta.
Syria's OPCW voting rights were suspended in 2021 over its refusal to cooperate with the body.
Damascus claimed seven Syrian troops were wounded in two mortar attacks involving chemical weapons during clashes with rebels in the village of Kharbit Massasneh, in the...