Fifty-eight people were killed while dozens more were wounded in what has been called a chemical attack on a town held by rebels in northwest Syria, says a monitoring organization.
Reports by the Syrian Observatory for Human Rights said that strikes by either Russian jets or the Syrian government caused a number of people to choke.
Unconfirmed reports later said that aircraft fired rockets at clinics that had been treating survivors from the previously bombing in Khan Sheikhoun.
The government of Syria has denied repeatedly the use of chemical weapons. If this is confirmed however, it would be one of Syria’s most deadly chemical attacks since the beginning of the civil war more than six years ago.
A charity ambulance service director in Idlib said he was given the news of the strikes at 6:45 local time.
When three ambulances of his arrived where the air strikes had hit, only 20 minutes later, rescue personnel found people who were choking, he said.
The rescue personnel were still there hours later trying to move the injured from one medical facility to another due to hospitals being overcrowded.
It was reported that 67 people died and over 300 had been injured, while Step news agency which is pro-opposition had the death toll as high as 100.
Medical sources had been cited by Syrian Observatory as reporting 11 children had been amongst those killed and that symptoms amongst those affected included vomiting, foaming of the mouth and fainting.
The EMC or Edlib Media Center which is also pro-opposition posted many photos of people being treated, along with images that appeared to be bodies of seven or more children in a pickup truck. No confirmation was made of the authenticity of the images.
There was no confirmation by the Syrian Observatory of the substance dropped, but EMC officials said their opinion was that it had been sarin the nerve agent.
The province of Idlib, where Tuesday’s air strikes hit, is controlled largely by rebel factions that have an alliance and the jihadist group linked to al-Qaeda known as Hayat Tahrir al Sham.
This region has regularly been targeted by air strikes by the Syrian government and Russia, as well as the multinational coalition led by the U.S. against the Islamic State militant group.
The main opposition alliance in Syria, the National Coalition has accused Syria President Bashar al-Assad and his government of the attack Tuesday in Khan Sheikhoun and said the Security Council in the UN must investigate it immediately.