The UK, France and the US have proposed a UN Security Council resolution to condemn a suspected gas attack in Syria which has killed at least 100 people.

It calls on the Organisation for the Prohibition of Chemical Weapons to quickly reveal its findings on Tuesday's attack in Idlib province, where 400 people were injured.

The draft resolution "condemns in the strongest terms the use of chemical weapons" in Syria, in particular the attack on Khan Sheikhun, and expresses "outrage" over the use of toxic gases in the six-year war.

It also urges UN Secretary-General Antonio Guterres to report monthly on whether the Syrian government is co-operating with an international inquiry into the use of chemical weapons across the war-torn country.

Diplomats say the resolution is likely to be put to a vote when the UN Security Council holds an emergency meeting on Wednesday.


Image: A Syrian medic runs for cover during the airstrikes which hit the hospital in Khan Sheikhun

Distressing footage from the town of Khan Sheikhoun showed people choking and fainting in the aftermath of the attack - with some victims left foaming at the mouth.

Rescue workers hosed down children to wash away any chemicals from their skin and gave them oxygen.

Mohammed Hassoun, an activist in nearby Sarmin, said: "Because of the number of wounded, they have been distributed around in rural Idlib.

"They were unconscious, they had seizures and when oxygen was administered, they bled from the nose and mouth."

Other videos showed dead children being covered with blankets, and bodies being loaded into trucks.

Image: A Syrian man is taken by civil defence workers following a suspected toxic gas attack in Khan Sheikhoun

The Syrian Observatory for Human Rights says the attack was believed to have been carried out by government jets, but the Syrian military has denied responsibility and said it would never use chemical weapons.

Russia's defence ministry has also denied carrying out any airstrikes in the area.

While the attack has been met with international condemnation, the United States' response to the strike has been criticised.

In a statement, President Trump called the assault "reprehensible" - but took the unusual step of saying that Barack Obama's strategy for Syria was partly to blame.

"These heinous actions by the Bashar al Assad regime are a consequence of the past administration's weakness and irresolution," Mr Trump wrote.

Image: Dozens of children were hurt in the suspected gas attack

US Secretary of State Rex Tillerson said Russia and Iran bore "great moral responsibility" for the bloodshed caused by the chemical attack.

White House officials including Press Secretary Sean Spicer had suggested in recent days that President Assad's departure was not necessary for peace - and Syrians should be able to decide his fate.

But Republican Senator John McCain said the latest chemical attack showed otherwise, adding: "In case it was not already painfully obvious: the notion that the Syrian people would be able to decide the fate of Assad or the future of their country under these conditions is an absurd fiction.

"The recent statements by US officials suggesting otherwise only serve to legitimise the actions of this war criminal in Damascus."

Image: More than 60 people were allegedly injured in the attack

Samantha Power, former US ambassador to the UN, tweeted: "Backed by Russia and Iran, declared permanent by Trump, Assad regime in Syria feels safe to do what it wants. Gassing people is what it wants."

The UK is co-hosting a major aid-pledging conference for Syria later on Wednesday, with Foreign Secretary Boris Johnson and International Development Secretary Priti Patel attending the event in Brussels.

Mr Johnson has said he is determined for the conference to "step up international assistance to the most vulnerable people affected by the conflict".

Idlib province is almost entirely controlled by the Syrian opposition and is home to 900,000 people displaced by the war.

Rebels, including former al Qaeda affiliates, have vowed to avenge the apparent gas attack, calling on fighters to "ignite all the fronts".