United Nations investigators report Syrian air force used sarin gas in Khan Sheikhoun

The UN Commission of Inquiry on Syria said at least 83 people a third of them children were killed in the April 4 sarin attack on the town of Khan Sheikhun

Anas Diyab, who was present at the site immediately after the attack, told the report's investigators that the air strike "aimed to cause a humanitarian catastrophe, and [deny] access to treat those whom were affected by the chemical attack - thus killing as many people as possible".

Noting concerns about the impact of global coalition air strikes on civilians, the report highlighted USA operations which hit civilians.

Syrian forces have used chemical weapons more than two dozen times during the country's civil war, including in the deadly attack that led to USA air strikes on regime planes, United Nations war crimes investigators said on Wednesday.

Furthermore, the U.N. Report acknowledged that USA air strikes on a mosque in Al-Jina in rural Aleppo in March that killed 38 people, including children, failed to take precautions in violation of worldwide law, but did not constitute a war crime.

At least 83 people died when a Su-22 jet dropped a bomb filled with the nerve agent Sarin on Khan Sheikhoun, a report by a commission of inquiry says.

The following month, then US President Barack Obama says the use or even movement of such weapons would be a "red line" for his administration.

The Assad regime has repeatedly denied using chemical weapons.

But following an attack on the Damascus suburb of Ghouta the following year, the United States struck a deal brokered by Russian Federation which saw the bulk of Syria's supplies of sarin removed from the country. But it has no capacity to prosecute any party, underscoring the geopolitical constraints that hamstring the world's response to the war.

Targeting medical facilities and healthcare personnel is a war crime.

This UN report exposes the hollowness and cynicism of the Obama administration in its dealings with Russian Federation and the American people. These attacks constitute clear violations of global humanitarian law and the Convention on Chemical Weapons, the report notes, which the Syrian Arab Republic ratified in 2013 following a previous sarin attack. But the media - ignoring the unprecedented withdrawal of a redline which severely damaged USA credibility - played along with the fiction and thousands of Syrian civilians died.

Images of the youngest casualties are believed to have figured in President Donald Trump's calculation to order missile strikes on a Syrian government airstrip days later, marking the first direct American military intervention against Syrian President Bashar Assad.

At least 38 people were killed in the attack, including a woman and three boys ranging from 6 to 13 years old.