A video published by the Islamic State of Iraq and the Levant (ISIL) group's media centre has purported to show images and last statements of nine people who took part in the Paris attacks that killed 130 people.
It was not possible to independently verify the authenticity of the footage, which showed the men delivering anti-Western diatribes and concluded with an apparent threat to attack Britain.
Laith Alkhouri, of Flashpoint Global Partners, which monitors the group's social media, said the "video meets all the right criteria of an authentic and official [ISIL] release".
The video was uploaded to ISIL's official Telegram channel and showed some of the attackers wearing camouflage fatigues in a desert location before the time of the Paris attacks.
Several of them were shown beheading hostages of the ultra-hardline group, a tactic it has frequently used.
"These are the last messages of the nine lions of the caliphate who were mobilised from their lairs to make a whole country, France, get down on its knees," a narrator in the video said.
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On the night of November 13, 2015, nine men, split into three groups, attacked a sports stadium, a string of cafes and a concert hall. An arrest warrant has been issued for another man, Salah Abdeslam, who fled to Belgium the following day.
The attackers are identified in the video by noms de guerre referring to their nationalities - three French, four Belgian and two Iraqis, referred to as Ali al-Iraqi and Ukashah al-Iraqi.
The two could be the suicide bombers who tried to attack the Stade de France stadium. They carried Syrian passports assumed to be forged and could not be formally identified. Seven other dead attackers have already been identified.
The video showed footage of British Prime Minister David Cameron expressing solidarity with the French people after the attacks, and concluded by flashing a slogan on the screen saying: "Whoever stands in the ranks of kafir [infidels] will be a target for our swords."
A spokesman for Cameron had no immediate comment.
The French foreign ministry declined a request from Reuters news agency to comment on the video. A spokeswoman for the National Security Council at the White House also had no comment.
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