"The United States and its allies have no proof and, without even waiting for the Organisation for the Prohibition of Chemical Weapons to take a position, have carried out this military attack," said the foreign ministry in a statement.
They "are responsible for the regional consequences of this adventurist action," it added.
Iran is the key backer alongside Russia of Syrian President Bashar al-Assad, providing military advisors and "volunteer" ground forces.
Seven Iranians were killed in an air strike on a Syrian military base on Monday, which Iran said was carried out by Israel.
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
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