A day after a suspected chemical weapons strike in Syria killed more than 70 people, world powers are trading accusations and denials as investigations into the attack continue.
Experts are still evaluating exactly what happened, but there's widespread consensus that deadly chemicals were involved in the attack on Khan Shaykhun in Idlib province.
The Syrian Observatory for Human Rights reports that 72 people there were killed by toxic chemicals, including 20 children and 17 women.
The World Health Organization has also received reports of scores of fatalities from deadly chemicals. "According to Health Cluster partners on the ground treating the patients, at least 70 people have died and hundreds more have been affected," the WHO wrote.
"Opposition activist videos show rescue workers hosing down survivors and the bodies of purported victims, showing no outward wounds," NPR's Alison Meuse reports from Beirut. "In one video, nine pale-faced children are loaded in the back of a truck, staring lifelessly into space."
It's not entirely confirmed what the chemicals were, but experts suspect a powerful nerve agent. Doctors Without Borders says victims were showing symptoms consistent with a chemical "such as sarin gas or similar compounds."
In the immediate aftermath of Tuesday's attack, international leaders — including British Foreign Secretary Boris Johnson and President Trump — censured Bashar Assad's regime for the apparent use of chemical weapons against civilians.
On Wednesday, Trump said the attack "crossed a lot of lines with me."
"When you kill innocent children, innocent babies, little babies, with a chemical gas that is so lethal, people were shocked to hear what gas it was, that crosses many, many lines, beyond a red line, many, many lines," Trump said, adding, "These heinous actions by the Assad regime cannot be tolerated."
At an emergency U.N. Security Council meeting Wednesday, U.S. Ambassador Nikki Haley delivered a pointed message, saying that Russia and Iran "have no interest in peace" and that the U.S. may need to act on its own.
"When the United Nations consistently fails in its duty to act collectively, there are times in the life of states that we are compelled to take our own action," she said.
Envoys from Russia had a different response to the attack.
"The main task now is to have an objective inquiry into what happened," Russia's deputy U.N. ambassador Vladimir Safronkov told the Security Council, according to The Associated Press. "Up to now all falsified reports about this incident have come from the White Helmets or the Syrian Observatory for Human Rights based in London which have been discredited long ago."
Russia has an alternate narrative of events, as Charles Maynes reports for NPR from Moscow.
"Russia's defense ministry says Syrian warplanes indeed carried out the strikes, but that civilian deaths were caused when those bombs struck a hidden ammunition depot that contained chemical weapons that belonged to terrorist groups on the ground," Maynes says. "Russia maintains the Assad government destroyed its entire chemical arsenal under a deal Moscow brokered with the Obama administration back in 2013."
That explanation has been challenged as "completely unsustainable and completely untrue" by a British chemical weapons expert who spoke to the BBC.
"Axiomatically, if you blow up Sarin, you destroy it," he told the BBC.
This blame-trading is not new in the Syrian conflict. In 2013, hundreds of civilians died in an attack on a Damascus suburb that used sarin gas. Afterward, the regime and its Russian allies claimed that rebel fighters may have used the chemical weapons. The Obama administration quickly rejected that explanation. A U.N. inspection confirmed the use of weapons, but did not attribute any blame.
The use of chemical weapons is a war crime, prohibited under a number of international treaties.
In 2013, after the sarin attack on Damascus, Assad's government agreed to hand over all of its remaining chemical weapons stockpile.
But in the last month alone, chemical weapons have been reportedly used at in Syria least three times, according to NATO chief Jens Stoltenberg.
Ongoing investigations might confirm the type of weapon used Tuesday and who deployed it. But key questions will still remain — including where the weapons came from, and how the world will respond.