What we know about the Syria strikes

Who was involved?

At a Pentagon briefing Friday, US officials described the strikes as a joint operation consisting of British, American and French forces.

"Today the nations of Britain, France, and the United States of America have marshaled their righteous power against barbarism and brutality," said US President Donald Trump, during a separate announcement from the White House, Friday.

Shortly after Trump's statement, UK Prime Minister Theresa May released a statement saying she had "authorized British armed forces to conduct coordinated and targeted strikes to degrade the Syrian Regime's chemical weapons capability and deter their use."

A statement released by the French President Emmanuel Macron, Friday, said that a "red line set by France in May 2017 has been crossed. So, I ordered the French armed forces to intervene tonight, as part of an international operation in coalition with the United States of America and the United Kingdom and directed against the clandestine chemical arsenal of the Syrian regime."

What was hit?

In announcing the strikes Friday, Trump said he had ordered "precision strikes on targets associated with the chemical weapon capabilities" of the Syrian regime.

Gen. Joseph Dunford, chairman of the Joint Chiefs of Staff, told reporters three sites were targeted:

A scientific research center in Damascus. A chemical weapons storage facility, located west of Homs. A chemical weapons equipment storage facility and command post near Homs.

Syrian state TV said missiles targeting Homs were intercepted and did not cause damage, though CNN has been unable to verify this report.

Russia's Defense Ministry said most of the missiles fired by the US, UK and France were shot down by Syrians using Soviet-era air defense systems, according to a report from state-sponsored Sputnik News.

What were the casualties?

Three civilians were wounded in Homs after "several" missiles were intercepted by Syria air defense systems, Syria state TV said. Witnesses on the ground in Damascus reported hearing explosions in the Syrian capital, where more than a million people live.

Are the strikes over?

Trump said the US was "prepared to sustain this response until the Syrian regime stops its use of prohibited chemical agents," however, he maintained that "America does not seek an indefinite presence in Syria."

At a Pentagon briefing, Dunford said "this wave of airstrikes is over," but defense officials added they are prepared for a sustained campaign until the Syrian regime ceases its alleged use of chemical weapons.

What weapons were involved?

Military and defense officials told CNN that at least one US Navy warship operating in the Red Sea participated in Friday's strikes, as well as US B-1 bombers.

A statement from the British Ministry of Defense said that four Royal Air Force Tornado GR4's were used in the strikes, launching Storm Shadow missiles at a "former missile base -- some 15 miles west of Homs."

France said it used missiles fired from Rafale fighter jets.

Was Russia warned?

Dunford said the US "specifically identified" targets to "mitigate the risk of Russian forces being involved."

He added normal communication lines were used in the run-up to the strike to ensure clearance of airspace, but said targets were not coordinated with the Russians.

Have Syria and Russia responded?

Russian President Vladimir Putin issued a statement Saturday saying the Kremlin "seriously condemns" the attack on Syria, which he called an "act of aggression against a sovereign state ... at the forefront of the fight against terrorism."

He said the strike had been carried out "without the sanction of the United Nations Security Council, in violation of the UN Charter, norms and principles of international law," and that Russia was calling for an immediate UN Security Council meeting.

In a statement following the strikes, Anatoly Antonov, Russian ambassador to the US, said Moscow's "warnings have been left unheard."

"We warned that such actions will not be left without consequences," he said. "Insulting the President of Russia is unacceptable and inadmissible. The US -- the possessor of the biggest arsenal of chemical weapons -- has no moral right to blame other countries."

In a statement posted on Facebook, Russia's Foreign Ministry spokeswoman, Maria Zakharova, said "After this statement the American and other Western mass media should understand their responsibility in what is happening."

Meanwhile, an official with the US-led coalition fighting ISIS in Syria said pro-regime and Russian forces in Syria are showing no signs of retaliation against US and coalition troops in the country.

What have we learned about the Douma attack?

More than 70 people in Syria's rebel-held town of Douma reportedly died while sheltering in basements -- 43 off whom showed symptoms consistent with exposure to "highly toxic chemicals," according to the World Health Organization (WHO).

The WHO, citing reports from health partners on the ground, also said that about 500 people went to the hospital showing signs of exposure to "toxic chemicals" in Douma.

The Syrian government and Russia, its key ally, have vehemently denied involvement and accused rebels in Douma of fabricating the chemical attack claims.

A team of inspectors from the Organization for the Prohibition of Chemical Weapons (OPCW) were on route to the site of the alleged attack before the strikes were launched against Damascus and Homs.