"This evening, I have authorised British armed forces to conduct coordinated and targeted strikes to degrade the Syrian regime's chemical weapons capability and deter their use," she said in a statement.
UK's Defence Ministry has confirmed that four RAF Tornado jets took part in the Syria strike along with French and US forces.
The Pentagon had informed that 59 Tomahawk cruise missiles were launched from two US vessels in the eastern Mediterranean. This strike reportedly destroyed 20 per cent of the Syrian Air Force.
This was the first time that the US had directly attacked Syrian forces since the beginning of the civil war in 2011.
Syrian state television also reported a US attack, in coordination with France and Britain, on Syria.
The strikes carried out by the US-led forces targeted three Syria's chemical weapons arsenal facilities. A research facility close to Damascus was hit, a chemical weapons storage facility around Homs and a command post were the targets of US-led strike.
US defense officials have said that about 100-120 missiles were launched by American forces against the Syrian regime on targets purportedly housing chemical weapons.
4) France joins in: French President Emmanuel Macron said that France had joined the US and Britain in an ongoing operation of strikes to target "the capacities of the Syrian regime to produce and use chemical weapons".
"We cannot tolerate the normalisation of the use of chemical weapons," he said in a statement issued shortly after huge explosions were heard in Syria's capital early Saturday followed by the sound of aeroplanes overhead.
For Macron, "the facts and the responsibility of the Syrian regime are not in doubt," concerning the "deaths of dozens of men, women and children" in what he said was a chemical weapons attack on April 7 in Douma.
"The red line set by France in May 2017 has been crossed," he said.
5) US says they have proof of chemical weapons in Syria: The United States has proof that Syrian leader Bashar al-Assad's regime launched a chemical weapons strike last weekend on the then rebel-held suburb of Douma, State Department spokeswoman Heather Nauert said today.
"I'm not going to say which day we absolutely knew that there was proof. The attack took place on Saturday, we know for a fact that it was a chemical weapon," she told reporters.
"We know that there are only certain countries like Syria that have delivery mechanisms and have those types of weapons." Asked whether she could say that the United States has proof that Assad's regime was behind the strike, Nauert said: "Yes.
6) US makes a case for military action in the United Nation: Prior to the strikes,US Ambassador Nikki Haley told the UN on Friday that no decision had been taken about military action against Syria, but the use of force would be in response to multiple chemical attacks carried out by President Bashar al-Assad's forces.
Haley made clear that the US administration was taking time to assess the full implications of military strikes on Syria after Russia warned that it could lead to a dangerous US-Russian war.
Addressing the Security Council, Haley laid out Washington's case for resorting to force, challenging Russia's claim that military action would be in violation of international law.
"Our president has not yet made a decision about possible action in Syria," Haley said.
7) Syria claims right to self-defence: At the United Nations, Syria warned on Friday that it will have "no other choice" but to defend itself if the West initiates military action.
"This is not a threat. This is a promise," Syrian Ambassador Bashar Jaafari told the UN Security Council.
The ambassador invoked Article 51 of the UN charter that recognises the right to self-defence by any state if it comes under attack.
If Britain, France and the United States take military action, "we would have no other choice expect applying Article 51 that gives us the right to defend ourselves," said Jaafari.
8) Russia says UK staged the chemical weapons attack: The Russian military on Friday said it had proof that an alleged chemical weapons attack in Syria's Eastern Ghouta was staged on orders from London.
Russian defence ministry spokesman Igor Konashenkov said the military had "proof that testifies to the direct participation of Britain in the organising of this provocation in Eastern Ghouta".
He said Britain had told the White Helmets, who act as first responders in rebel-held areas, to fake the suspected chemical attack in the town of Douma.
9) UN Chief says Syria most serious threat: UN chief Antonio Guterres today mentioned that Syria represents "most serious threat" to international peace and security and urged all stakeholders to avoid any move that could result in worsening the situation for the Syrian people.
United Nations Secretary-General Antonio Guterres yesterday said that the "Cold War is back with a vengeance", as he warned against the escalation of tensions among rival factions -- the US and Russia -- over the suspected use of chemical weapons in Syria.
The UN Chief further said, "The mechanisms and the safeguards to manage the risks of escalation that existed in the past no longer seem to be present."
10) Russia reacts to Syrian strikes: Reacting to the US-led strikes,Russia’s foreign ministry said that the Syrian capital was attacked at the very moment when the country had a chance for a peaceful future.
Russia’s foreign ministry also said that the Western media has some responsibility for the Syria attack, which was based on its reports.
AFP quoting Russian Defence Ministry reported that "a significant number" of missiles fired by the coalition were intercepted.
The Russian Ambassador to the US said, "A pre-designed scenario is being implemented. Again, we are being threatened. We warned that such actions will not be left without consequences."
Statement by the Ambassador Antonov on the strikes on #Syria:
A pre-designed scenario is being implemented. Again, we are being threatened. We warned that such actions will not be left without consequences.
All responsibility for them rests with Washington, London and Paris.