The number of fatalities caused by an alleged chemical attack on a rebel-held town in northern Syria has risen to 72, including 20 children, a British war monitor says.
The Syrian Observatory for Human Rights said that the victims of the attack that struck the town of Khan Sheikhoun in north Idlib province on Tuesday also included 17 women, and that unidentified warplanes were continuing to carry out strikes in the wake of the alleged chemical bombing.
The UK Foreign Secretary Boris Johnson, who was arriving in Brussels for a conference on Syria, blamed the forces of President Bashar al-Assad for the chemical attack, saying: "all the evidence I have seen suggests this was the Assad regime."
The US has also blamed the Assad administration.
The United Nations Security Council was due to hold an emergency meeting on the matter later on Wednesday, upon the request of the UK and France.
The UN Secretary-General, Antonio Guterres called for a clear investigation into the events, describing it as a "moment of truth".
Assad's government has denied involvement in the attacks, as has one of their main international allies, Russia, which said the chemical explosion was a result of Syrian Army airstrikes hitting rebel chemical arms factories.
In the immediate wake of the attack, opposition activists on the ground blamed Syrian aviation for the bombing.
The Syria Civil Defense volunteer organization, popularly known as the White Helmets, said up to 300 could have been exposed to the toxic chemical gases.
The events in Idlib have sparked an international outcry as images of children struggling to breathe whilst receiving medical treatment were shared widely online and published across the world's media outlets.
A Syrian rebel commander denied Russia's statement that poison gas had leaked from an insurgent chemical-weapons depot.
Hasan Haj Ali, commander of the Free Idlib Army rebel group, said no rebel military positions in the area were targeted on Tuesday.
"Everyone saw the plane while it was bombing with gas," he told Reuters from northwestern Syria.
"Likewise, all the civilians in the area know that there are no military positions there, or places for the manufacture (of weapons). The various factions of the opposition are not capable of producing these substances," he said.
He called the Russian statement "a lie".
