France and Britain on Monday dismissed a video released by the Islamic State group showing jihadists who carried out the November Paris attacks training and committing atrocities in what is likely Iraq or Syria.
And the Europol police agency warned that the extremist group was planning more "large-scale terrorist attacks" in Europe, with analysts saying the footage showed there was a high level of co-ordination and planning behind the Paris attack.
Two months after IS gunmen and suicide bombers attacked Paris nightspots, killing 130 people, the group published a 17-minute video showing four Belgians, three French citizens and two Iraqis all of whom took part in the assault and either died on the night, or in a subsequent police raid days later. Entitled "Kill wherever you find them", the video shows nine men delivering final messages inciting lone-wolf attacks and, in particular, threatening Britain.
Seven are shown outdoors behind victims who are later decapitated or shot, while another is seen carrying out target practice.
Purported ringleader Abdelhamid Abaaoud, who was in Europe for several months before the attacks, is the only one speaking inside a room.
The fighters' battlefield names are given, and the video confirms for the first time that IS trained the attackers and sent them to carry out the assault, rather than merely inspiring supporters from afar.
"The clear preparation that went into it... specifically highlights how this was a plot that was directed by core IS," said Raffaello Pantucci of the Royal United Services Institute (RUSI) in London.
"The dilemma has always been: was IS actually employing assets against the West or was it just creating noise to throw sand in our faces? Now it's quite clear they are attacking."
The video features images of French President Francois Hollande and British Prime Minister David Cameron with targets superimposed on them.
Referring to the 70-nation coalition fighting IS, Abaaoud warns that "the more you wage war against the Islamic State, the more it will expand... for we are terrorists."
But Hollande, who is on a visit to India, dismissed the threats.
"Nothing will deter us, no threat will make France waver in the fight against terrorism," he told reporters.
And Cameron's office said the video showed "an appalling terrorist group that's clearly in decline and in retreat."
With French and Arabic songs playing in the background, the video calls for the murder of Westerners, and names two of the Paris streets where several of the attacks took place.
It also praises Amedy Coulibaly, who killed four hostages at a Jewish supermarket in January 2015, two days after the Kouachi brothers staged a deadly attack on the Charlie Hebdo magazine, killing 12. The video, produced by IS's Al-Hayat Media Centre, shows television news footage of the night of the attacks, and the chaos in Paris, with red targets superimposed over special forces in the streets of the French capital.