(RNN) - The United States has launched strikes against Syria, President Trump said in an address to the nation on Friday night.
The strikes are in response to a suspected gas attack on the rebel-held city of Douma last weekend.
The U.S. is conducting the strikes in coordination with Britain and France, the president said.
Reuters and CNN reported witnesses have heard explosions in Damascus, and smoke can be seen rising outside the city.
Agence France-Presse reported "huge blasts" in the Syrian capital.
A Syrian opposition official, Hadi Al Bahra, tweeted "the first missile targeted an area in Mount Qasioun."
Mount Qasioun, in the east of Damascus, is where the palace of Syrian President Bashar Al Assad is located.
According to the World Health Organization, the attack on the Damascus suburb of Douma by the Assad regime may have exposed around 500 people to toxic chemicals.
Graphic images of small children being treated by medics and bodies foaming at the mouth circulated after the attack.
The president called the attack "the crime of a monster" in his address to the nation.
"Tonight I ask all Americans to say a prayer for our noble warriors and our allies as they carry out their missions," he said.
Earlier this week, missiles were launched at the T-4 airbase in central Homs Governorate. Russia and Syria blamed Israel for the strikes.
Following a sarin attack on Syrian civilians in the town of Khan Sheikhoun in April 2017, Trump ordered strikes on the Shayrat air base in Homs.
In that strike, 59 Tomahawk cruise missiles were launched from the USS Ross and USS Porter in the Mediterranean. They destroyed or damaged a number of Syrian military aircraft and infrastructure at the base.
The Syrians said as many as 16 people were killed in the strikes, including nine civilians in the surrounding area.
Operations resumed at the air base just a couple days later.