Britain and the US have accused the Syrian regime and its Russian allies of staging a chemical weapons attack in Aleppo and blaming it on Syrian rebels.
In coordinated statements, the US and UK said it believed Russia and the Assad regime had carried out the attack against civilians in Aleppo on November 24.
The regime claimed at the time that the attack had injured 100 people and had been carried by rebel fighters in Idlib, the last opposition held province in Syria.
“The United States strongly refutes this narrative and has credible information that pro-regime forces likely used teargas against civilians in Aleppo on November 24,” the US State Department said in a statement.
“The United States has information indicating Russian and Syrian personnel were involved in the teargas incident, and believes that both countries are using it as an opportunity to undermine confidence in the ceasefire in Idlib.”
The Foreign Office said the November 24 attack was likely either “either a staged incident intended to frame the opposition, or an operation which went wrong and from which Russia and the regime sought to take advantage”.
Both countries urged the regime to allow inspectors from the OPCW, the chemical weapons watchdog, to investigate the site.
“We caution Russia and the regime against tampering with the suspected attack site and urge them to secure the safety of impartial, independent inspectors so that those responsible can be held accountable,” the US said.
The Russian embassy in Washington hit back at the claims in a Facebook post.
“The Russian Defense Ministry does not rule out that the US Department of State’s allegations about the recent toxic chemicals attack in Syria’s Aleppo are aimed at distracting the public attention from the crimes of the US aviation in the east of the Middle Eastern country,” it said.
The statement appeared to be referencing reports that civilians in the eastern province of Deir Ezzor had been killed by recent airstrikes from the US-led coalition.
The US and UK are both concerned that the regime is biding its time before launching an assault on Idlib, where around three million civilians from across Syria are taking shelter.
The Syrian regime appeared on the verge of launching an assault in September but last-minute diplomacy by Turkey averted an attack.
However, Turkey and Western countries are concerned it may only be a matter of time before the regime moves ahead with its attack.