"Last night, a false alarm that Syrian air space had been penetrated triggered the blowing of air defence sirens and the firing of several missiles," a military source told state news agency SANA.

"There was no external attack on Syria," the source added.

In the early hours of Tuesday, Syrian state media reported that air defence systems had shot down missiles over Homs province.

It branded the incident an "aggression" but did not name a specific country.

Big explosions were heard overnight near Shayrat air base, southeast of Homs city, and near Damascus where two other air bases are located, the Syrian Observatory for Human Rights reported.

Syrian military positions in Homs province have been bombed twice in just over a week.

On Saturday, a volley of American, British, and French missiles slammed Syrian military positions in Homs province and around Damascus.

And on April 9, Syria accused Israel of striking the T-4 air base in Homs.

Both the US and Israel appeared to deny involvement in Monday night's incident.

An Israeli military spokesman said he was "not aware" of the incident and US defence spokeswoman Heather Babb said there were no American operations in the area.

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