The US has carried out a missile attack against an air base in Syria in response to a suspected chemical weapons attack on a rebel-held town.
The attack comes just days after dozens of civilians, including many children, died in the suspected nerve gas attack in the town of Khan Sheikhoun in Idlib province.
Fifty-nine Tomahawk cruise missiles were fired from two US Navy ships in the Mediterranean, the Pentagon said.
President Donald Trump said they hit a base from which the Syrian government launched Tuesday's chemical attack.
The Kremlin, which backs the Syria government, has condemned the US strike.
Dmitry Peskov, spokesman for Russian President Vladimir Putin, called it "an act of aggression against a sovereign nation".
Mr Trump said he had acted in America's "vital national security interest" to prevent the use of chemical weapons.
The UK government called the US strike "an appropriate response to the barbaric chemical weapons attack".
Details of damage or casualties has not been given but the governor of Homs province said there had been deaths and parts of the base were on fire.
However, the Syrian Observatory for Human Rights, a UK-based monitoring group, said at least four Syrian soldiers had been killed.topics from