Brace yourselves to not be shocked: He’s a Muslim convert.

(Reuters) – France believes a second French militant appears on a beheading video released by Islamic State at the weekend, government spokesman Stephane Le Foll said on Wednesday.

Officials said on Monday that one of the men shown herding prisoners to their execution was Maxime Hauchard, a Frenchman Muslim convert who left for Syria in 2013. Further analysis suggested another French citizen also took part in the video.

“It seems that there is a second Frenchman,” Le Foll told BFM TV. “We are checking his identity,” he said declining to confirm a name circulating in French media. […]

Thousands of Western volunteers have joined Islamic State, which is waging a bloody war in both Syria and Iraq. More than 1,130 French citizens are involved in jihadi cells linked to the two countries, of which 376 nationals, are in the region.

According to the prosecutor’s office, the second French suspect was also a Muslim convert, who traveled to Syria in Aug. 2013 and was known to intelligence services.

The 15-minute video posted online shows the decapitations of 18 men who Islamic State said were pilots and officers loyal to Syrian President Bashar al-Assad, as well as the severed head of U.S. aid worker Peter Kassig.