A HEAVY flight of US-led coalition warplanes have reportedly been seen flying over the Iraqi border as a nerve gas counter attack looms.

Civilian planes were said to have been ordered to clear the airspace over Syria by the US military for at least 48 hours as flight radar shows aircraft diverting.

5 Flight data shows planes being diverted from Syrian airspace as a 48 hour clearance was reportedly ordered by the US military Credit: Flight radar

European air traffic controllers issued a "rapid alert" for airlines in the Eastern Mediterranean over the possibility of air strikes into Syria within the next 72 hours.

The European Aviation Security Agency's (EASA) warning of possible launches of air-to-ground strikes or cruise missiles comes as the US, Britain, France and allies weigh up retaliatory measures to a suspected chemical weapon attack in Syria.

Nafiseh Kohnavard, a reporter for the BBC, tweeted: "Airlines that are still using Syria’s airspace have received a request to change their corridors for the next 48 hours.

"Sources say that all military bases and important centres of the Syrian government are on high alert as a US attack is expected."

President Donald Trump says he'll ​'​forcefully​'​ respond to an alleged chemical weapons attack in Syria

It comes after a series of horrendous chemical attacks left 70 men, women and children dead and 500 wounded near Damascus.

On Tuesday, President Trump cancelled a foreign trip to speak with other world leaders including Britain and France, about launching a military strike as early as the end of the week.

Prime Minister Theresa May has agreed with her American and French counterparts that the international community needs to respond after Syria denied being responsible for the chemical weapons attack.

Mr Trump has said the apparent poison gas attack in Syria will be "met forcefully", but did not give a time-frame for any retaliatory action.

5 Activist groups claim at least 500 people were treated after a gas attack Credit: Getty - Contributor

Downing Street said Mrs May and the two leaders agreed that the international community "needed to respond to uphold the worldwide prohibition on the use of chemical weapons".

A spokeswoman said Mrs May held separate calls with the two leaders on Tuesday and that they agreed the reports of a chemical weapons attack in Syria were "utterly reprehensible" and that they would "continue working closely together".

Amid the tough talk from the White House, the US military appeared to be in position to carry out any attack order.

A Navy destroyer, the USS Donald Cook, got underway in the eastern Mediterranean on Monday after completing a port call in Cyprus.

5 Medical workers treating toddlers following the alleged poison gas attack Credit: AP:Associated Press

5 A medical worker gives a young child oxygen after the alleged attack Credit: AP:Associated Press

The guided missile destroyer is armed with Tomahawk cruise missiles, the weapon of choice in a US attack one year ago on an airfield in Syria following an alleged sarin gas attack on civilians.

Mrs May sidestepped questions about whether Britain would be involved in military action during a visit to Cambridge earlier on Tuesday.

She is expected to comment on the situation again on Wednesday during a visit to Birmingham.

The attack in Douma happened late on Saturday amid a resumed offensive by Syrian government forces after the collapse of a truce with the Army of Islam rebel group.

Syrian opposition activists and rescuers said poison gas was used on the rebel-held town near the capital, an allegation strongly denied by the Assad government.

Video said to show missile flying overhead that hit Syria military airport leaving 'several dead'

Families were reportedly found suffocated in their homes and shelters, with foam on their mouths.

Reports suggested more than 500 people, mostly women and children, were taken to medical centres with difficulty breathing, foaming at the mouth and burning sensations in the eyes.

The attack comes almost exactly a year after a chemical atrocity in the northern Syrian town of Khan Sheikhoun killed dozens of people.

That attack prompted the US to launch several dozen Tomahawk cruise missiles at a Syrian air base.

Russia and Syria have blamed Israel for an attack on a Syrian military airport on Monday that reportedly killed at least 14 people.

5 An apparent attack on an airbase came just a day after a chemical strike in Douma

More to follow...

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