Syrian anti-aircraft defences have shot down missiles fired at the Syrian air base of Shayrat, in Homs province, and another base north-east of the capital Damascus, Syria's state television, official news agency and pro-Iranian Hezbollah media say.
A top Russian chemical weapons protection expert, Igor Kirillov said experts from Organization for the Prohibition of Chemical Weapons are set to visit Douma tomorrow. The Syrian state television report did not, however, specify who may have fired the missiles.
The US Department of Defense said there was "no USA military activity in that area at this time".
Hezbollah's AlManar TV reported that six missiles targeted Shayrat and three were aimed at Dumair military airport outside Homs on Monday.
The tripartite Western aggression occurred days after the United States accused the Syrian government of an alleged attack with chemical weapons in the city of Duma, Eastern Ghouta region, an accusation rejected by the authorities of this country.
There has been speculation that Israel launched the strikes.
Israel has previously carried out air strikes during the conflict in Syria, targeting Iran-backed militias fighting alongside the forces of Syrian President Bashar al-Assad.
A local reporter for The Arab News said Israeli warplanes were spotted in Syrian airspace just before the missiles were reported.
Asked about the missile attack, an Israeli military spokesman told Reuters, "We don't comment on such reports".
That attack killed four Iranian military personnel - but Israel did not confirm or deny involvement.