MPs have overwhelmingly backed UK air strikes against so-called Islamic State in Syria, by 397 votes to 223, after an impassioned 10-hour Commons debate.

Four Tornado jets took off from RAF Akrotiri, Cyprus, after the vote. Their destination has not been confirmed.

A total of 66 Labour MPs sided with the government as David Cameron secured a larger than expected Commons majority.

The PM said they had "taken the right decision to keep the country safe" but opponents said the move was a mistake.

A further four fighter jets remain on standby at the air base, which is used for bombing missions to Iraq and from where reports have suggested air strikes against IS targets in Syria could also be launched.

Two of the four Tornados landed back in Cyprus just over three hours later, shortly before 03:00 GMT.

BBC defence correspondent Jonathan Beale said they had left RAF Akrotiri with three 500lb Paveway bombs each and returned to base without those weapons.

The Ministry of Defence is expected to give details of their targets later on Thursday, he added.

BBC political correspondent Robin Brant said while the Ministry of Defence was not confirming where the jets were heading, it "would not be surprising" if they were bound for Syria.

He said the RAF "has been preparing to be involved in these air strikes ", joining the coalition of other Western forces attacking IS in Syria, "for months".

Analysis by political editor Laura Kuenssberg

David Cameron has achieved his long-held goal.

Intervening against the extremist forces who call themselves the Islamic State in Syria - it seemed impossible less than a month ago. But in the weeks since the Paris attacks, the prospect of extending bombing strikes into Syria from Iraq has taken on a reluctant inevitability.

Planes may be dropping bombs by tonight.

But for the prime minister, with this, his third big foreign intervention - Libya, Iraq, now Syria - pulling together a wider plan to achieve real peace is a far more complex task, one he acknowledges the UK cannot complete on its own.

Former Cabinet ministers Alan Johnson, Yvette Cooper and Margaret Beckett also spoke in favour of military action while deputy leader Tom Watson and former acting leader Harriet Harman also voted with the government.

But former leader Ed Miliband was among the 153 Labour MPs to vote against.

Reacting to the vote, aides to Mr Corbyn said a majority of the parliamentary party and the shadow cabinet had backed his position and the leader's authority had been "enhanced".

Shadow International Development Secretary Diane Abbott said Mr Corbyn was more in line with the public than the prime minister, telling the BBC that "very soon public opinion will tire of Cameron's war".

The vast majority of Conservative MPs supported military action, with just seven - far fewer than expected - voting against.

The SNP, all of whose 54 MPs opposed military action, said it was disappointed and feared the outcome would lead "to Iraq and Libya all over again".

But the United States, which along with France, Russia and other countries are already conducting missions in Syria, welcomed the vote, saying "it looks forward to having UK forces flying with the coalition over Syria".

Courtesy BBC