BRITAIN and the US rushed to accuse Syria of April’s nerve gas attack yesterday after a report avoided blaming any side.

An Organisation for the Prohibition of Chemical Weapons (OPCW) investigation determined the nerve agent sarin was used in the town of Khan Sheikhoun on April 4.

It is leaving a joint UNOPWC probe to determine if President Bashar al-Assad’s government or the al-Qaida-affiliated Hetesh forces occupying the town are to blame.

But the US State Department claimed on Thursday night: “The facts reflect a despicable and highly dangerous record of chemical weapons use by the Assad regime.”

And British Foreign Secretary Boris Johnson chimed in yesterday, saying: “The Assad regime almost certainly carried out this abominable attack,” urging other UN security council members “to hold those responsible for this atrocity to account.”

Both the US and the OPCW were at pains to defend investigators’ failure to visit Khan Sheikhoun, relying on samples provided by the rebels.

The Russian Foreign Ministry said the reports used “dubious data” driven by “political orders” to blame the Syrian government.

Minister Sergey Lavrov pointed out the OPCW was “not sure that the sarin found there had been airdropped in bombs.”

“They don’t know how the sarin ended up there, yet tensions have been escalating for all these months.”

Moscow and Damascus have maintained the attack was perpetrated by extremists to give the US a pretext for the massive cruise missile strike that followed.

On Monday the US claimed Syria was planning “another” attack and threatened further retaliation.

Washington’s UN ambassador Nikki Haley said any attacks on Syrian people — regardless of the perpetrator — would be pinned on the government and its allies Russia and Iran.

Syria’s Sana news agency reported on Thursday that eight civilians were killed in the eastern town of Suwar when US-led coalition aircraft bombed their homes.

Syrian troops surrounded the last Isis pocket in Aleppo province yesterday afternoon.

Israel said it had bombed Syrian forces fighting Hetesh in western Quneitra province for the fourth time in a week after an “errant projectile” landed in the occupied Golan Heights.

Widely reported rumours surfaced on Thursday that the Pentagon would soon pull its troops and Free Syrian Army proxies out of the Tanf border post in southern Syria.