LONDON (Reuters) - Britain struck Syria with air-launched cruise missiles on Saturday in partnership with the United States and France to try to cripple its chemical weapons facilities and stop what Prime Minister Theresa May cast as a global slide towards their greater use.

Four Tornado jets from the Akrotiri base in Cyprus fired eight missiles at a military facility near Homs where it was assessed that Syria had stockpiled chemicals, the Ministry of Defence said.

May said the strike was “limited and targeted” and came after intelligence indicated that Syrian military officials had coordinated a chlorine attack in the Damascus suburb of Douma on April 7.

She said the missile attacks had been aimed at deterring President Bashar al-Assad’s further use of chemical weapons and were not an attempt to topple the Syrian government.

“This is not about intervening in a civil war. It is not about regime change,” May said in a statement minutes after U.S. President Donald Trump announced the strikes.

May later told reporters that the Western missiles had struck a chemical weapons storage and production facility, a chemical weapons research center and a military bunker involved in chemical weapons attacks.

By launching strikes without prior approval from parliament, May dispensed with a non-binding constitutional convention dating back to the 2003 invasion of Iraq. She said speed was essential and that military action was in the national interest.

“RIGHT AND LEGAL”

“It was both right and legal to take military action,” May said, adding that she would update parliament on Monday.

May made clear the strike was a specific response to the Douma attack, which killed up to 75 people, including children.

She dismissed as “grotesque and absurd” a claim by Russia, which joined the war in 2015 to back Assad, that Britain had staged the Douma attack.

Her office issued a statement detailing what it said was the legal justification for military action, saying Assad had used chemical weapons since 2013 and the blocking of United Nations action by Russia and other allies of Syria left no alternative to “truly exceptional” use of force.

“Such an intervention was directed exclusively to averting a humanitarian catastrophe caused by the Syrian regime’s use of chemical weapons, and the action was the minimum judged necessary for that purpose,” Downing Street said.

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May referred to last month’s nerve agent attack on former spy Sergei Skripal and his daughter in the English city of Salisbury, which Britain has blamed on Russia. Moscow has denied any involvement.

“We cannot allow the use of chemical weapons to become normalized – either within Syria, on the streets of the UK or elsewhere,” May told reporters in Downing Street.

She said almost a century of global aversion to the use of chemical weapons had been eroded in Douma and Salisbury.

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“BOMBS WON’T SAVE LIVES”

May’s office said she had spoken to the Crown Prince of Saudi Arabia, Mohammed bin Salman, Turkish President Tayyip Erdogan, German Chancellor Angela Merkel and the prime ministers of Italy, Australia and Canada about the strikes.

It said they all agreed with her on “the importance of restoring the international norm that the use of chemical weapons is never acceptable”.

May also spoke to Trump and French President Macron, and they agreed the strikes had been a success, Downing Street said.

The small Northern Irish political party that props up her government said May was justified in taking such action.

However, opposition Labour leader Jeremy Corbyn, a fervent anti-war campaigner, called the strikes “legally questionable” and said May should have recalled parliament from recess and “not trailed after Donald Trump”.

“Bombs won’t save lives or bring about peace,” he said. “Britain should be playing a leadership role to bring about a ceasefire in the conflict, not taking instructions from Washington and putting British military personnel in harm’s way.”

Many politicians including some in May’s own Conservative Party, had backed his call for parliament to be asked before any military strike.

A BMG poll, taken before the strikes and published by the Independent newspaper on Saturday, indicated that 28 percent of Britons backed air strikes, with 36 percent opposed.

Former prime minister David Cameron lost a parliamentary vote on air strikes against Assad’s forces in 2013 when 30 Conservative lawmakers voted against action, with many Britons wary of entering another conflict after interventions in Iraq, Afghanistan and Libya failed to bring stability to the region.