British officials studying latest video from Islamic State
British officials are studying the latest video from terror group Islamic State, which apparently shows those responsible for the Paris attacks committing earlier atrocities.
The film, released on Sunday, also features threats to attack Britain - stating in English that whoever stands with "unbelievers" will be "a target for our swords".
The 17-minute video ends with images of an extremist holding a severed head along with footage of Prime Minister David Cameron delivering a speech.
But Mr Cameron's official spokeswoman said that IS - also known as Daesh, Isis or Isil - was "clearly in decline and in retreat".
Responding to the video, President Francois Hollande said that France will not allow threats to weaken its resolve against terrorism.
He confirmed that the country will remain in the state of emergency imposed following the November 13 attacks which killed 130 at a concert hall, bars and a sports stadium in the French capital.
The primarily French-language video, provided online by the Site Intelligence Group - which monitors jihadi websites, shows nine of the perpetrators of the Paris murders before they left for France.
They are seen beheading and shooting captives, and one of the militants holds a victim's head up and says, in a reference to one of Paris's most famous landmarks, "Soon on the Champs Elysees".
Downing Street confirmed that UK experts were looking at the video.
The PM's spokeswoman told a regular Westminster media briefing: "We are in the process of examining this latest propaganda video, which is another move from an appalling terrorist group that is clearly in decline and in retreat".
The new video emerged after a series of military setbacks for IS in its strongholds in Syria and Iraq.
And it came as Afghan President Ashraf Ghani promised to "bury" the group in his country, where IS claimed responsibility for a suicide attack in the city of Jalalabad earlier this month.
Mr Ghani told the BBC: "We have particularly in the last week effected a significant focus on Daesh and managed to inflict very severe damage on them."
IS atrocities against women and older people had alienated Afghans from the group "to a remarkable degree", he said.
"It could be a point of no return for Daesh," said Mr Ghani.
"We will bury Daesh ... Daesh is not the product of Afghanistan and it is not an Afghan phenomenon. It needs to be dealt with and it will be dealt with severely."