The United States has accused Russia and Syria of fabricating a story about chemical weapons use by Syrian rebels.
The United States said Friday it had "credible information" that the account by Russia of chemical weapons use in Syria in November was false and said that Russian and Syrian forces instead had fired tear gas, State Department spokesman Robert Palladino said.
Russia's defense ministry had said on Nov. 24 that Syrian rebels fired grenades containing chlorine near the government-held city of Aleppo. Syrian state media also reported the account, saying that about 100 Syrians were hospitalized with breathing difficulties.
However, Palladino accused Russia and Syria of creating the false report as "an opportunity to undermine confidence in the cease-fire in Idlib," the last stronghold of rebels fighting Syrian President Bashar al-Assad.
Russia responded to the purported attack with air raids on Idlib.
"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," he said.
Palladino said that the United States is concerned that Syrian officials have maintained control of the site to "potentially fabricate samples and contaminate the site before a proper investigation of it by the Organization for the Prohibition of Chemical Weapons."
The United States, the United Nations and other Western governments have repeatedly accused Assad's forces of using chemical weapons over the last several years. Syria's government has denied the charges and has blamed the attacks on rebels.