US attacks Syrian air base

The United States has fired 60 missiles at a Syrian airbase in response to deadly poison gas attack.

The US has fired roughly 60 missiles at a Syrian airbase in response to a deadly poison gas attack. (AAP)

The United States has attacked a Syrian air base with roughly 60 cruise missiles in response to a chemical weapons attack it blames on President Bashar Assad.

US officials say the Tomahawk missiles were fired from two warships in the Mediterranean Sea, targeting a government-controlled air base in Syria.

The officials says Syrian government aircraft killed dozens of civilians by using chlorine mixed with a nerve agent, possibly sarin, earlier this week.

The bombing represents US President Donald Trump's most dramatic military order since taking office. The Obama administration threatened attacking Assad's forces for previous chemical weapons attacks, but never followed through.