The United States launched a military strike Thursday on a Syrian government airbase in response to a chemical weapons attack that killed dozens of civilians earlier in the week.

On President Donald Trump’s orders, U.S. warships launched 59 Tomahawk cruise missiles at the airbase that was home to the warplanes that carried out the chemical attacks, U.S. officials said.

Six people have reportedly been killed in the bombing.

A CNN article called the incident “a substantial escalation of the U.S. military campaign in the region, and could be interpreted by the Syrian government as an act of war.”