She said U.S. President Donald Trump had spoken with his French counterpart Emmanuel Macron about Syria earlier on Friday. It did not mention the overall number of missiles intercepted by Syrian forces.
He said there was a heightened "danger of escalation" because of the Russian military presence in Syria.
The UN Security Council, tasked with maintaining worldwide peace and security, has been riven, with Moscow virulently denying the Douma attack took place, or postulating that it was carried out by rebels.
At the United Nations meanwhile, diplomats were mulling a draft resolution put forward by Sweden and obtained by AFP, that would dispatch a "high-level disarmament mission" to rid the country of chemical weapons "once and for all".
"We will not stand by whilst innocent civilians, including women and children, are killed and made to suffer".
Brig. Gen. Ali Mayhoub, who read the statement on Syrian TV, said "our air defenses effectively shot down a lot of them".
A team of experts from the global chemical weapons watchdog, the Organisation for the Prohibition of Chemical Weapons, was traveling to Syria and will start its investigations on Saturday, the Netherlands-based agency said.
"Such attacks will not deter our armed forces and allied forces from persisting to crush what is left of the armed terrorist groups", the military said.
There have been periodic allegations of chlorine attacks and other types of chemical weapons use by the Syrian regime since then, however.
Some non-governmental organizations, including White Helmets, claim that chemical weapons were used in Douma, Eastern Ghouta, on April 7. Syria denies responsibility and says it gave up its chemical arsenal.
And those options are still being discused with allies France and Britain.
"Assad's recent attack and today's response is a direct result of Russia's failure to respond", Trump said.
He added that "those responsible must be held accountable".
"I have done so because I judge this action to be in Britain's national interest".
The Syrian-American Medical Society (Sams) said more than 500 people had been found with symptoms "indicative of exposure to a chemical agent" after the attacks. "The suffering it causes is horrendous". We can not purge the world of evil, or act everywhere there is tyranny.
In the days between the attack in Douma and the US-led response, Washington and Moscow clashed repeatedly in duelling statements and debates.
"The facility which was struck is located some distance from any known concentrations of civilian habitation, reducing yet further any such risk", the MoD said in a statement. He again spoke to Trump after the attacks were launched, an aide said.More news: Attention Gmail users: your emails might 'self-destruct' soon
"Never said when an attack on Syria would take place".
In New York, Russia's United Nations ambassador warned the priority in Syria was to avert US-led strikes that could lead to a confrontation between the world's two preeminent nuclear powers.
Several months later (and long after the US missile strike), a United Nations panel concluded it was confident the Syrian government had carried out the attack. The airstrikes were "not about intervening in a civil war (or) regime change", May said.
"We later discovered the bodies of people who had suffocated from toxic gases", he added.
In that strike, 59 Tomahawk cruise missiles were launched from the USS Ross and USS Porter in the Mediterranean.
However, it noted that the missiles were taken down by decades-old systems, including Neva surface-to-air missiles that were designed in the 1950s.
A photo released by Iranian media reportedly shows the T-4 air base in central Syria after a missile barrage attributed to Israel on Monday April 9, 2018.
Vassily Nebenzia, Moscow's ambassador to the United Nations, said he "cannot exclude" war between the United States and Russian Federation and urged Washington and its allies to refrain from military action against Syria.
The second target was a chemical weapons storage facility west of the city of Homs.
France has also stationed several Mirage and Rafale fighter jets in Jordan and the United Arab Emirates.
Joseph Dunford, Washington's 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. The veto garnered broad condemnation from United States allies.
May ignored a convention that she seek parliamentary approval before launching any military action.
The US, UK and France have bombed multiple government targets in Syria in an early morning operation targeting alleged chemical weapons sites, the BBC reports. The demonstrators waved victory signs - and Syrian, Russian and Iranian flags - clapped their hands, danced and honked their vehicle horns.
Hudson believes President Donald Trump's decision to use air power against Syria sends a very important signal to Bashar al-Assad, Vladimir Putin and the rest of the world.
"We welcome this operation which has eased humanity's conscience in the face of the attack in Douma, largely suspected to have been carried out by the regime", the Turkish foreign ministry said in a statement. Some clapped their hands and danced, other drove in convoys, honking their horns in defiance. We thank them both.
State TV broadcast live from the square where a large crowd of civilians mixed with men in uniforms, including an actor, lawmakers and other figures.
"She's in an impossible position", said one Tory MP select committee chair.