(Reuters) - Syrian Arab Air Force pilots flying Sukhoi Su-22 military planes and a helicopter dropped bombs containing poisonous chlorine and sarin nerve gas on a village in the country's western Hama region in March 2017, a new team at the global chemical weapons watchdog has concluded in its first report.

The special investigative unit was established by members of the Organisation for the Prohibition of Chemical Weapons (OPCW) in 2018 to identify perpetrators of illegal attacks. Until now the OPCW had only been authorised to say whether chemical attacks occurred, not who perpetrated them.

Officials in the government of Syrian President Bashar al-Assad and its military backer Russia have repeatedly denied using chemical weapons and accuse insurgents of staging attacks to implicate Syrian forces.