Russia defended its ally Damascus on Wednesday in the face of an international outcry over a suspected chemical attack that killed scores of civilians, saying a Syrian air strike hit a “terrorist warehouse” containing “toxic substances.”

The claim by the Kremlin came as the international community continued to point its finger at the Syrian regime over the deadly attack, with UK Foreign Secretary Boris Johnson blaming President Bashar Assad for deliberately carrying out the bombing that has left at least 72 people dead and hundreds more wounded.

The UN Security Council was to hold an emergency meeting later Wednesday on the attack.

“According to the objective data of the Russian airspace control, Syrian aviation struck a large terrorist warehouse near Khan Sheikhoun,” the Russian defense ministry said in a statement, adding that the warehouse contained “toxic substances.”

It housed “a warehouse making bombs, with toxic substances,” said the ministry, without stating if the strike was deliberate.

“The arsenal of chemical weapons” was destined for fighters in Iraq, the ministry said, adding that the information was “completely reliable and objective.”

He claimed the use of such weapons “by terrorists has been repeatedly proved by international organizations as well as official authorities” in Iraq.

This photo provided Tuesday, April 4, 2017 by the Syrian anti-government activist group Edlib Media Center, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. (Edlib Media Center, via AP)

This photo provided Tuesday, April 4, 2017 by the Syrian anti-government activist group Edlib Media Center, shows victims of a suspected chemical attack, in the town of Khan Sheikhoun, northern Idlib province, Syria. (Edlib Media Center, via AP)

The statement did not specify whether the Syrian regime knew there were chemical weapons there and pointed the finger at “terrorists” who they say hold the toxic arms.

At least 72 civilians including 20 children died in the suspected chemical attack on Tuesday in the rebel-held Syrian town of Khan Sheikhoun in Idlib province in the northwest.

Al Jazeera put the death toll in the attack above 100 people as victims succumbed to their wounds.

If confirmed, the attack would be among the worst incidents of chemical weapons use in Syria’s brutal civil war, which has killed over 320,000 people since it began in March 2011.

It unfolded in the early hours of Tuesday morning, with airplanes carrying out strikes that released “toxic gas” on Khan Sheikhoun, in the northwestern province of Idlib, according to witnesses and a monitoring group.

“We ran inside the houses and saw whole families just dead in their beds,” resident Abu Mustafa told AFP of the attack’s aftermath.

“Children, women, old people dead in the streets.”

The Syrian Observatory for Human Rights, a Britain-based monitor, said at least 160 people suffered the effects of the gas, with medical sources reporting incidents of vomiting, fainting, breathing problems and foaming at the mouth.

An unconscious Syrian child is carried at a hospital in Khan Sheikhun, a rebel-held town in the northwestern Syrian Idlib province, following a suspected toxic gas attack on April 4, 2017. (AFP PHOTO / Omar haj kadour)

An unconscious Syrian child is carried at a hospital in Khan Sheikhun, a rebel-held town in the northwestern Syrian Idlib province, following a suspected toxic gas attack on April 4, 2017. (AFP PHOTO / Omar haj kadour)

Syria’s opposition blamed Assad’s forces, saying the attack cast doubt on the future of peace talks, but the army denied any involvement, blaming “terrorist groups” for using “chemical and toxic substances.”

Medic Hazem Shehwan told AFP he saw victims with “pinpoint pupils, convulsions, foaming at the mouth and rapid pulses.”

Medics worked frantically in the hours after the attack to treat a steady stream of patients, administering oxygen and hosing down victims to wash off chemical residue.

Even as they worked, air strikes hit a medical facility treating victims, an AFP correspondent said, bringing rubble down on top of medics and patients.

Air strikes hit Khan Sheikhoun again on Wednesday morning, the Observatory said. There were no immediate details on a toll.

In Europe, Johnson said all evidence pointed to Assad being behind the attack.

“All the evidence I have seen suggests this was the Assad regime… using illegal weapons on their own people,” Johnson said as he arrived for a Syria aid conference in Brussels.

“What it confirms to everybody is that this is a barbaric regime which has made it impossible for us to imagine them (having) authority over Syria after this conflict,” he added.

The Brussels conference, co-chaired by the EU and UN, is a followup to last year’s London meeting which raised $11 billion (10 billion euros) for humanitarian aid programs in the devastated country.

It is also meant to support UN-sponsored peace talks in Geneva where mediator Staffan de Mistura has reported some very modest progress in solving a conflict which has claimed more than 320,000 lives and displaced most of the Syrian population.

Assad’s future role is a key sticking point — the rebels and their international backers demand that he must step down.

But Assad refuses to budge and his key ally in Moscow has backed him to the hilt against the rebels and shows no sign of changing tack.

EU foreign affairs chief Federica Mogherini urged the international community to press ahead with the peace talks, which were made even more urgent after Tuesday’s suspected chemical weapons attack.

“We need to give a push, a strong push to the political talks in Geneva. We have to unite the international community behind these negotiations,” Mogherini said.

Rebel groups led by former al-Qaeda affiliate Fateh al-Sham Front vowed revenge for the attack.

Syria officially relinquished its chemical arsenal and signed the Chemical Weapons Convention in 2013, to avert military action after it was accused of an attack outside Damascus that killed hundreds.

But there have been repeated allegations of chemical weapons use since, with a UN-led investigation pointing the finger at the regime for at least three chlorine attacks in 2014 and 2015.

Britain, France and the United States were to present a resolution to the Security Council Wednesday calling for the OPCW to quickly report findings on the attack.

But it was unclear if Russia would veto the measure, as it has often done with previous Security Council resolutions concerning Syria.

The text calls on Syria to provide flight plans, flight logs and other information on its military operations on the day of the assault.