4 children among 9 civilians dead in US Syria strike: Media

A US missile strike targeting an airbase in central Syria killed nine civilians, including four children on Friday, state news agency SANA reported.

The news agency said five of the civilians, among them three children, were killed in the village of Shayrat just outside the base of the same name.

"An American missile also hit the village of Al-Hamrat, which killed four civilians including a child," it added.

The US on Friday launched a massive military strike on a Syrian air base in retaliation to a "barbaric" chemical attack on civilians allegedly by embattled President Bashar al-Assad's regime and asked all "civilised" countries to join it to end the killing of innocent people.

On President Donald Trump's orders, US warships in the Mediterranean Sea launched between 50-60 Tomahawk cruise missiles at the Shayrat air base, in Homs governorate, where the warplanes that carried out the chemical attacks are based, US officials said.

The move signals a dramatic shift in Trump's position on whether the US should take military action against Assad's regime. Trump, during his campaign for president, had opposed any such move.

The missiles from two US warships hit at 3:45am and targeted the base's airstrips, hangars, control tower and ammunition areas.

Speaking from his Mar-a-Lago resort in Florida, Trump said he ordered targeted missile strikes at the Syrian airfield.

A military official quoted on Syrian TV said the US action caused material damage.

Describing the chemical attack on innocent civilians as "horrible", Trump said President Assad took the lives of helpless men, women and children.

"It was a slow and brutal death for so many. Even beautiful babies were cruelly murdered in this very barbaric attack. No child of God should ever suffer such horror," he said.

"It is in vital national security interest of the United States to prevent and deter use of deadly chemical weapons," Trump told reporters.

The military action comes after Tuesday's deadly chemical attack that officials said used chlorine mixed with a nerve agent, killing 86 people, including 27 children, in the rebel-held town of Khan Sheikhun in northwestern Syria.

Moscow slammed the US strike on a Syrian airbase Friday as "aggression against a sovereign state", and suspended a bilateral agreement to help avoid clashes in the skies over the war-torn country. "President Putin considers American strikes on Syria aggression against a sovereign state in violation of international norms, and under an invented pretext," said the statement by the Kremlin press service posted on the official website.