The international chemical weapons watchdog says mustard gas was used in Syria in August - leading to the death of a child.

The Organisation for the Prohibition of Chemical Weapons (OPCW) has found with "utmost confidence" that the chemical was used during fighting between rebels and jihadists in the town of Marea, close to Allepo.

The group says that during the incident "at least two people were exposed to sulfur mustard, and that it is very likely that the effects of this chemical weapon resulted in the death of an infant".

Experts from the organisation also found that toxic chemicals - including chlorine - were likely used "as a weapon" in an attack in Idlib province in March.

However a team investigating a third alleged incident in Jobar on August 29th - after which the Syrian government claimed their soldiers had 'sustained casualties' from the use of toxic chemicals - could not confidently determine the use of chemical weapons.

The OPCW says that they might conduct further investigations into the incidents if any more 'credible' information is made available by the Syrian government or other groups.

A report will now be submitted to the UN Security Council.