Would this be a suburb that’s thick with “North Africans” by any chance?
When my mom visited an artist friend of hers in Vence many years ago, she took some pics for future studies. Saw an Algerian skinning a goat and she began taking pics. He pulled the knife on her. Thankfully, she got out alive when her friend did a lot of talking.
I don't know about Bobigny specifically, but it is in the department of Seine-Saint-Denis, which wikipedia (yeah, I know, but politically incorrect facts on wikipedia are usually reliable) suggests has Islam as its most practiced religion, and which also includes Clincy-sous-Bois, where the two Muslim "youths" managing to get electrocuted while fleeing the police set off the big riots in 2005