Their comics confronted Fox News correspondents when they spotted them reporting live in Paris. In one video, two of the show’s correspondents pretended to be American journalists venturing into supposedly forbidden areas and, in slapstick fashion, cowering by a Turkish kebab shop and a couscous restaurant and falling to the ground at the sound of a jackhammer.

Image Mr. Barthès reviewed his script in his dressing room before going on stage. He has hosted the show since it began in 2004. Credit... Capucine Granier-Deferre for The New York Times

Representatives of “Le Petit Journal” also showed up at the New York offices of Fox News on Thursday to seek comment, Mr. Barthès said, until security turned them away.

Mr. Barthès said that his show was unable to obtain any response from Fox News, so he turned to his viewers for help, giving the email addresses of Fox executives. When the show posted the information on Twitter, he said, they had 7,000 retweets in five minutes.

The theme was picked up by others on social media who expressed mock horror at the “danger” in Paris. A food guide site mapped the best places to dine in the so-called lawless zones, including a bakery where the owner had won awards for baguettes.

The commotion began this month when Steve Emerson, identified as a terrorism expert, told the host Sean Hannity, “there are no-go zones” throughout Europe ruled by Muslims. He then elaborated in an interview with another Fox host, Jeanine Pirro, claiming that the entire city of Birmingham, England, was a place where “non-Muslims simply don’t go in.”

On the day the Charlie Hebdo attackers were killed, Nolan Peterson, who on his website describes himself as a freelance writer and a combat veteran, went on Fox News on and identified what he called 741 Muslim-dominated “no-go zones” around France and said the areas reminded him of his time in Afghanistan and Iraq. Even the British prime minister, David Cameron, reacted to the Birmingham claim, saying, “When I heard this, frankly, I choked on my porridge.” He called Mr. Emerson “an idiot.”