By Agence France-Presse
AFP's correspondent in Damascus said several consecutive blasts were heard at 4:00 am local time (0100 GMT), followed by the sound of airplanes overhead. Smoke could be seen emerging from the northern and eastern edges of the capital.
Syrian state television simultaneously reported a US attack on Syria, in coordination with France and Britain.
"Syrian air defence blocks American, British, French aggression on Syria," state television said.
Trump said the strikes would aim to deter chemical weapons use by the Syrian government, a week after a suspected chemical attack outside Damascus left more than 40 people dead.