In that time, 15 diners were killed at the nearby Le Petit Cambodge, an Asian restaurant near a canal that runs through the 10th Arrondissement, and at a restaurant across the street, Le Carillon. Gunmen, according to witnesses, sprayed the establishments with bullets from a black vehicle and then raced away.

Emily Murphy, 28, an architect, had gathered at the packed Carillon with about a dozen of her colleagues. Unable to find a table inside, they stood on the sidewalk, drinks in hand. As Ms. Murphy was preparing to leave to meet a girlfriend in another part of town, she heard what sounded like a small explosion behind her. A man standing next to her pushed her to the ground and told her not to move.

“I was in the middle of the sidewalk. The shooting was going on and on, and I was so scared he could see me and was going to come closer,” she said, referring to a gunman. She said she felt something like a “scratch” on her right leg but only realized after the shooting stopped that she had been grazed.

At the time, Ms. Hua, 38, the fashion blogger, was eating with three friends on a terrace at Madame Shawn, a Thai restaurant in the area, when she and her friends heard a series of loud bangs. She said they had initially thought the noise was related to gang clashes that sometimes blighted the area.

“It took us a while to register what had happened,” she said. “I looked at my iPhone and I had many worried calls. This is one of the most densely populated areas in Paris. There is no place that is more full on a Friday night. This is a place where young people hang out. It was a hit at the soul of Paris.”