In pics | Scores killed, many injured including children in ‘horrific’ Syria gas attack

The British-based Syrian Observatory for Human Rights said the attack was believed to have been carried out by Syrian government jets. It caused many people to choke and some to foam at the mouth.

A suspected Syrian government chemical attack killed scores of people, including children, in the northwestern province of Idlib on Tuesday, a monitoring group, medics and rescue workers in the rebel-held area said.

A Syrian girl receives treatment at a makeshift clinic following reported air strikes by government forces in the rebel-held town of Douma. (AFP Photo)

The US government believes the chemical agent sarin was used in the attack, a government source said, adding it was “almost certainly” carried out by forces loyal to Syrian President Bashar al-Assad.

UN’s Syria mediator Staffan de Mistura also said the “horrific” chemical attack had come from the air.

The Syrian military denied responsibility and said it would never use chemical weapons, echoing denials it has made over the course of the more than six-year Syrian civil war that has killed hundreds of thousands, created the world’s worst refugee crisis and drawn in nations such as Russia, Iran and the United States.

Syrian children receive treatment at a small hospital in the town of Maaret al-Noman in Syria’s northwestern Idlib province. (AFP Photo)

A wounded Syrian youth gestures at a makeshift clinic following reported air strikes by government forces in the rebel-held town of Douma. (AFP Photo)

A Syrian man and girl flee past a man carrying a folded stretcher in Hamouria. (AFP Photo)

A civil defence member breathes through an oxygen mask, after what rescue workers described as a suspected gas attack in the town of Khan Sheikhoun in rebel-held Idlib. (Reuters Photo)

A Syrian man is taken by civil defence workers to a small hospital following a suspected toxic gas attack in Khan Sheikhun. (AFP Photo)

A crater is seen at the site of an airstrike in rebel-held Idlib. (Reuters Photo)

If confirmed, the gas attack in Khan Sheikhoun would be the deadliest chemical attack in Syria since sarin gas killed hundreds of civilians in Ghouta near Damascus in August 2013. (AFP Photo)

The Syrian Observatory for Human Rights said those killed in the town of Khan Sheikhun, in Idlib province, had died from the effects of the gas, adding that dozens more suffered respiratory problems and other symptoms. (AFP Photo)

Syrians flee following a reported government air strike in Hamouria, in the eastern Ghouta region on the outskirts of the capital Damascus. (AFP Photo)

Bodies lie in the parking area of a hospital in Khan Sheikhun. The head of the health authority in rebel-held Idlib province said more than 50 people had been killed. (AFP Photo)

A still image taken from a video posted on a social media website on April 4, 2017, shows people lying on the ground said to be in the town of Khan Sheikhoun. (Reuters Photo)

A man holds an injured baby inside a Turkish ambulance as injured Syrian people enter into Turkey from the Cilvegozu border gate in Hatay province. (AFP Photo)