Syria chemical attack

Samples from 10 victims were analysed at four laboratories, OPCW head Ahmet Uzumcu said.

The attack on the rebel-held town killed at least 87 people.

The Syrian military denied using any chemical agents.

Its ally Russia, meanwhile, said an air strike hit a rebel depot full of chemical munitions - but this suggestion has been widely rejected.

The US responded to the attack by launching air strikes on a Syrian military airfield.

Footage following the incident showed civilians, many of them children, choking and foaming at the mouth.

In an exclusive video interview with AFP news agency, he said "there was no order to make any attack".

More than 80 people were killed in the rebel-held town of Khan Sheikhoun on 4 April, and hundreds suffered symptoms consistent with a nerve agent.

Witnesses said they saw warplanes attack the town but Russia says a rebel depot of chemical munitions was hit.

Shocking footage showed victims - many of them children - convulsing and foaming at the mouth. Sufferers were taken to hospitals across the border in Turkey.

Russia had agreed to ensure Syria's chemical weapons stockpiles were destroyed - and its failure to do this enabled the attack, he said.

G7 foreign ministers are preparing to meet in Italy later on Monday.

Talks will focus on how to increase pressure on Russia to distance itself from Syria's President Bashar Al-Assad.

On Tuesday, Mr Tillerson will continue from the G7 to Moscow, where he will meet his Russian counterpart, Sergei Lavrov.

Russia is the Syrian government's main ally, and helped facilitate a 2013 agreement to destroy Syria's chemical arsenal.