A cable news station in Paris has aired shocking video of French-speaking jihadists at work in Syria. The footage broadcast Thursday night on BFMTV played like a macabre postcard home, only the latest reminder that hundreds of French and thousands of European jihadists are waging war against Bashar al-Assad. The news channel has called it evidence that France’s own are “direct actors in the atrocities committed in Syria.”

The video excerpts are said to have been filmed over several days in February by French-speaking members of the Islamic State in Iraq and the Levant, also known as ISIS, a radical group of al-Qaeda dissidents. The brigade in the footage is said to comprise about 20 French nationals and 20 Belgians.

Heavily blurred for broadcast, the images provided to French journalists by supporters of the Western-backed Free Syrian Army are nevertheless plainly gruesome. Most disturbing perhaps is the juxtaposition of the young men all smiles —- for all appearances enjoying a summer holiday, footloose buddies on a camping trip—amid sheer horror.

“We used to haul jet skis, quads, and motocross bikes. Now, on the path to God, we haul apostates and miscreants. Those who combat us, those who combat Islam,” one woolly-capped, wispy-bearded twenty-something grins, speaking a mix of French and Arabic at the wheel of a blue Dodge pickup. “You can film my new trailer!” he tells the cameraman. The view swings past the truck’s cargo bed to a heap of bodies, seven or eight BFMTV tells us, who are said to be Syrian rebels and civilians freshly killed. Under a cloudless sky, their bodies are dragged without ceremony on a makeshift sled along the dirt of a plowed field to a mass grave.

Thousands of European nationals are believed to have traveled to Syria to join jihadist groups fighting to oust Assad. French media in recent months have narrated a disconcerting tick-tock of their country’s share of the fighters: Their comings and goings, arrests, even the anguish of their mothers. Interior Minister Manuel Valls in January estimated that 700 French nationals or residents of France were more or less involved in the Syrian conflict, that 250 were currently in Syria, 99 were in transit to get there, 150 had showed interest in going there, 76 had already returned, and that 21 had died on Syrian soil. The French anti-terrorist judge Marc Trévidic recently told Reuters of “a very clear accelerator, when the first generation of those who left came back to get their buddies.”

President François Hollande’s office announced Monday that a strategy and action plan had been decided in the battle against the Syrian jihadist networks and their recent radicalization, but details were promised for an unspecified later date.

The grisly footage obtained by BFMTV shows the French-speaking fighters arriving at a scene splayed with bodies. Bloody corpses are filmed up close. Deemed “apostates” by a man behind the camera, some appear to be fighters with Free Syrian Army insignia. Others are apparent civilians: a teenage boy in a Dolce & Gabbana jacket lies motionless beside a pile of plates he is assumed to have been carrying; a man in a kitchen lies dead in a pool of blood, next to the onion he is supposed to have been peeling when he was gunned down.

In the TV report, a BFM crew travels to Azaz, a town eight kilometers from the Turkish border, and finds a villa occupied until recently by fighters known locally as the “French Brigade,” said to be unable to converse fluently in Arabic with locals. At a roundabout in the town, one man recounts the Islamists’ taste for displaying the decapitated heads of foes atop a statue for all to see. On the same roundabout, a blurred line-up of heads features in a photo posted to a French-speaking jihadists' Facebook page last month: a nauseating spectacle that zealous followers are invited to “Like.”