The governments of the US, UK and France say 105 missiles were launched at three sites in Syria as part of a coordinated operation early on the morning of 14 April, at around 4am local time.
The air and sea strikes were a response to an alleged chemical attack in Douma a week before, which killed at least 42 people and injured hundreds.
Him Shinshar chemical weapons storage site
The chairman of the US joint chiefs of staff, Gen Joseph Dunford, said Him Shinshar was “the primary location of Syrian sarin and precursor production equipment”.
A total of 22 missiles from France, the United Kingdom and the United States hit this site, including eight British Storm Shadow missiles and nine American Tomahawk missiles.
The MoD said the facility was a former missile base, located around 15 miles west of Homs, where the Syrian regime was believed to keep a stockpile of chemical weapon precursors, which can be used to make blister agents such as mustard gas or nerve agents such as sarin.
Him Shinshar chemical weapons bunker
The site west of the city of Homs was an alleged underground chemical weapons storage facility, doubling as a command post.
Seven SCALP missiles hit the bunker, according to the US military.
The image below, released by the US Department of Defense, shows the damage up close.
Barzah research and development centre Damascus
The scientific research facility in Barzeh, north of Damascus, was purported to be the centre of Bashar al-Assad’s chemical weapons programme. Footage and photographs after the raid showed destroyed concrete office blocks and Syrian soldiers picking their way through the rubble.
According to Lt Gen Kenneth McKenzie, who directs the US military’s joint staff, 76 missiles were fired at the research centre in the Syrian capital, comprising 57 Tomahawk cruise missiles and 19 air-to-surface missiles.
In May last year, the BBC reported that the Barzah site was being used by the Syrian regime to install chemical weapons on long-range missiles, violating the 2013 agreement to eliminate chemical weapons from the country.
The image below, released by the US Department of Defense, shows the damage up close.