The strike on the Tayfur air base in the central province of Homs, came as international outrage mounts over an attack on Saturday in the rebel enclave of Eastern Ghouta.

"Several missiles hit the Tayfur airport. Our air defence systems are blocking the missile attack," state news agency SANA said early Monday.

It later added that there were "dead and wounded" in the strike, without giving exact casualty numbers.

The missile attack came shortly after US President Donald Trump issued a stark warning over an apparent "chemical" attack in Douma, the last rebel-controlled town in an eastern suburb of Damascus.

"Many dead, including women and children, in mindless CHEMICAL attack in Syria," Trump wrote on Twitter, lashing out at Syrian President Bashar al-Assad and Russia's Vladimir Putin, a key ally of the regime.

"President Putin, Russia and Iran are responsible for backing Animal Assad. Big price to pay," he said.

His comments came exactly a year and a day after the US fired cruise missiles at a Syrian air base in retaliation for a deadly sarin gas attack in 2017.

SANA first said the missile strike on the Tayfur base was a "suspected US attack," but later withdrew all reference to America.