Showed symptoms of a chemical attack

that a chemical weapons attack had taken place.

WHO also cited reports about the deaths of more than 70 people who sheltered in basements, saying 43 of those people who died had shown “symptoms consistent with exposure to highly toxic chemicals”.

The Organisation for the Prohibition of Chemical Weapons said it would send “shortly” a fact-finding mission to Douma. Meanwhile, airline pilots flying from the UK to Cyprus have been given a safety warning over military action in Syria.

The “rapid alert” was issued by European aviation authorities, telling pilots that “due consideration needs to be taken” of possible air-toground strikes or cruise missiles into Syria “within the next 72 hours”.

The notification from the European Aviation Security Agency (Easa) covers the Eastern Mediterranean/ Nicosia flight information region, which includes airspace over Cyprus. The alert, published by air traffic control group Eurocontrol, also warns of “intermittent disruption of radio navigation equipment”.

Around 50 flights were due to depart for Cyprus from airports across the UK yesterday, including services by easyjet, Ryanair, British Airways and Thomas Cook Airlines to Larnaca and Paphos.

Most carriers already avoid Syrian airspace due to previous warnings from aviation regulators in the UK and other countries, but the Easa alert could affect flights in neighbouring regions.

In July 2014, Malaysia Airlines Flight 17 was shot down over conflict-torn eastern Ukraine, killing 298 passengers and crew.

An international investigation found the missile used was taken into Ukraine from Russia, but the latter denied any involvement.