Damascus: An airbase in Syria's Homs province was hit by "several missiles" in a "likely attack by the US" on Monday, according to state media reports.
The Tayfur airbase, also known as T4, is located in a strategic position between the cities of Homs and Palmyra, reports CNN.
Citing a military source, the state-run Syrian Arab News Agency (SANA) said the attack had caused an unspecified number of deaths and injuries.
It said the airfield was targeted with several missiles. The Syrian air defence had responded and shot down eight incoming missiles, the agency added.
Video footage on social media in Lebanon showed aircraft or missiles flying low over the country, apparently heading east towards Syria.
However, the Pentagon has denied the Syrian claims of the airbase attack that comes hours after President Donald Trump tweeted "Animal Assad" would have a "big price to pay" for an alleged chemical weapons attack in the city of Douma.
"At this time, the Department of Defence is not conducting air strikes in Syria. However, we continue to closely watch the situation and support the ongoing diplomatic efforts to hold those who use chemical weapons, in Syria and otherwise, accountable," a Pentagon statement said early Monday.
On Sunday, Trump said there would be a "big price to pay" after the alleged chemical weapons attack in the rebel-held city of Douma, which the US blamed on Syrian President Bashar al-Assad.
In a series of tweets, Trump also slammed Russian President Vladimir Putin and Tehran, saying "Russia and Iran are responsible for backing Animal Assad".
It was not clear what retaliatory action Trump has in mind, but the issue is expected to be discussed at a "small group" meeting of the National Security Council on Monday, led by John Bolton on his first day as White House National Security Adviser, administration officials told CNN.
Last April, the US launched Tomahawk missiles at a Syrian airbase after Washington and others accused Assad's forces of perpetrating a deadly chemical weapons attack in Khan Sheikhoun that killed 80 people, which the Syrian military denied.
In Saturday's attack, toxic gas inside barrel bombs were dropped from helicopters over Douma that killed over 40 civilians.
Images showed people, including children, apparently dead and injured with some kind of spittle or foam in their mouths in makeshift medical centres.
The authenticity of the images could not be immediately confirmed.