A photo released on April 14, 2018 by the official Syrian Arab News Agency (SANA) shows an explosion on the outskirts of Damascus after Western strikes reportedly hit Syrian military bases and chemical research centres in and around the capital

Damascus (Syria) (AFP) - The United States, Britain and France carried out a wave of pre-dawn strikes against Syria’s regime Saturday in response to a suspected chemical weapons attack, lighting up the sky of Damascus as explosions shook the city.

Branding last week’s alleged gas attack the “crimes of a monster”, US President Donald Trump announced the action against President Bashar al-Assad’s regime in a White House address, defying fierce warnings from Damascus ally Russia.

A few minutes later, an AFP correspondent in Damascus heard a series of huge blasts and residents rushed to their balconies. For around 45 minutes, explosions echoed and the sound of warplanes roared over the city, as flashes flared in the distance.

When dawn broke, plumes of smoke could be seen rising from the city’s north and east.

In the biggest foreign military action so far against Syria’s regime, Western officials said a barrage of cruise and air-to-land missiles hit what they said were sites linked to chemical weapons development.

Map of Syria showing locations hit by overnight strikes

The targets included a scientific research facility in the Damascus area, a chemical weapons storage facility west of the city of Homs and a third location near Homs that contained both a command post and a chemical weapons equipment storage facility, the US military said.

But while Trump’s belligerent tweets this week seemed to raise the prospect of large-scale military action, Saturday’s strikes were narrowly targeted and the facilities hit had reportedly been evacuated in recent days.

Syrian state media reported only three people injured and Russia’s defence ministry said there were “no victims” among Syrian civilians and military personnel.

- ‘Evil and despicable attack’ -

A picture released by the French Defence audiovisual communication and production unit shows the launch of a cruise missile from a French military vessel in the Mediterranean sea towards targets in Syria

Trump said the strikes were a direct response to an alleged April 7 chemical attack on the rebel-held town of Douma that rescuers and monitors say killed more than 40 people.

“The evil and the despicable attack left mothers 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,” Trump said.

US Defence Secretary Jim Mattis called the strikes a “one-time shot” with no additional military action planned for now.

Assad, who has denied ever using chemical weapons and regularly denounces his opponents as “terrorists”, responded to the strikes with a defiant vow.

“This aggression will only make Syria and its people more determined to keep fighting and crushing terrorism in every inch of the country,” he said in comments published by his office.

Russia denounced the strikes as “aggressive actions” and called an emergency session of the UN Security Council.

US President Donald Trump addresses the nation on the situation in Syria April 13, 2018 at the White House in Washington, DC

Assad’s other key ally Iran also denounced the attack, with supreme leader Ayatollah Ali Khamenei describing Western leaders as “criminals”.

The targets appeared to steer well clear of any Russian personnel or equipment in Syria, where Moscow launched a military intervention in support of Assad in 2015.

The Russian military said the allies had fired 103 cruise missiles but that Syrian air defence systems managed to intercept 71 of them.

- Defiant rally in Damascus -

At a rally in central Damascus, 48-year-old Nedher Hammoud claimed to have seen missiles “being shot down like flies”.

“Let them do what they want, kill who they want… History will record that Syria shot down missiles – and not just missiles. It shot down American arrogance.”

Syrians wave the national flag and portraits of President Bashar al-Assad as they gather at Umayyad Square in Damascus on April 14, 2018, to condemn strikes carried out by the United States, Britain and France

The impromptu early morning rally saw crowds of people heading to the famed Umayyad Square to show their support for Assad, waving government flags and blaring patriotic songs.

Inspectors with the Organisation for the Prohibition of Chemical Weapons were due later Saturday to start work on a probe into the events of April 7 in Douma, the last rebel-held pocket of the onetime opposition stronghold of Eastern Ghouta near Damascus.

The OPCW said in a statement after the strikes that its fact-finding mission would continue.

The Jaish al-Islam rebel group in control of Douma said the suspected chemical attack forced them to agree to a Russia-brokered evacuation deal, paving the way for Syria’s government to secure Eastern Ghouta.

Mohammad Alloush, a key member of Jaish al-Islam, said Saturday the Western strikes had not gone far enough.

“Punishing the instrument of the crime while keeping the criminal – a farce,” Alloush wrote on Twitter.

Syrian state media reported that internal security forces had entered Douma on Saturday and that the town would be secured within hours.

The spectre of military strikes had hung over Syria since Trump reacted furiously to harrowing footage that surfaced of the aftermath of the attack in Douma.

French President Emmanuel Macron and British Prime Minister quickly rallied to the cause, saying the use of chemical weapons could not be tolerated.

France said it fired cruise missiles from frigates in the Mediterranean and deployed fighter jets from home bases as part of its strikes.

Britain’s defence ministry said that four British Tornado jets had fired Storm Shadow missiles at a base 15 miles (25 kilometres) west of Homs city.

- UN chief urges restraint -

In the days between the attack in Douma and the US-led response, Washington and Moscow clashed repeatedly in duelling statements and debates.

Moscow denied Assad had any role in the alleged attack, pushing a variety of alternative theories that peaked with a claim that Britain staged the event.

Royal Air Force tornado jets take off in the early hours from RAF Akrotiri airbase in Cyprus to conduct air strikes in Syria on April 14, 2018

Washington, Paris and London have nevertheless insisted that their own secret intelligence points to Assad’s guilt, and on Friday, a US spokeswoman said they had “proof.”

The Western leaders apparently found the evidence conclusive enough to launch a punitive strike, but other observers are concerned the crisis could escalate.

The Russian military had vowed to respond to any attack, and Russian President Vladimir Putin’s administration had repeatedly warned that Trump was taking America down a dangerous path.

UN Secretary General Antonio Guterres on Saturday called for calm, delaying a planned trip to Saudi Arabia to deal with the aftermath of the military action.

“I urge all member states to show restraint in these dangerous circumstances,” he said in a statement.