The United States, Britain and France carried out a wave of punitive strikes against the Syrian regime on Saturday in response to alleged chemical weapons attacks in the rebel-held Damascus suburb of Douma. Several consecutive blasts were heard at 4:00 am in Damascus, followed by the sound of airplanes overhead. Smoke could be seen rising from the northern and eastern edges of the capital. "A short time ago, I ordered the United States armed forces to launch precision strikes on targets associated with the chemical weapons capabilities of Syrian dictator Bashar al-Assad," President Donald Trump said, in a primetime address from the White House. "A combined operation with the armed forces of France and the United Kingdom is now under way. We thank them both." "This massacre was a significant escalation in a pattern of chemical weapons use by that very terrible regime," he said of the suspected deadly gas attack a week ago on Douma. "The evil and the despicable attack left mother and fathers, infants and children thrashing in pain and gasping for air. These are not the actions of a man. They are crimes of a monster instead." Joseph Dunford, Washingtons top general, said the strikes hit three targets near Damascus -- a scientific research center, a storage facility and command post -- and a chemical weapons storage facility near Homs. Syrian surface to air missile batteries had attempted to fire back, but there were no initial reports of allied losses, he added. Syrian regime media said air defenses were activated to block the attack as it published images of smoke clouds hanging over the capital. "The aggression is a flagrant violation of international law, a breach of the international communitys will, and it is doomed to fail," regime media said.  Dunford said Russias forces in Syria had been warned through existing "deconfliction" channels that western planes would be in Syrian air space, but Washington had not revealed the target sites or timing in advance. Defense Secretary Jim Mattis said no additional strikes were planned.  "We were very precise and proportionate, but at the same time, it was a heavy strike," he said.