PARIS — Police officers fanned out in the French capital on Monday in search of the man responsible for a shooting at a newspaper headquarters that left one man gravely wounded and the city on edge.

In what may be related episodes, a man opened fire later in the morning outside the headquarters of a major bank and there were reports that an armed individual in the same area had stopped a car and forced its driver to drive him to the Champs-Élysées.

Surveillance footage from the newspaper shooting indicated that the same man who opened fire there had brandished a shotgun on Friday at the headquarters of BFMTV, a Paris-based television news channel, threatening a senior editor before fleeing, the French news media reported.

Shortly after 10 a.m. on Monday, the gunman went through the front entrance of Libération, a left-leaning national daily, fired two blasts from a shotgun and fled, according to witnesses. A 27-year-old photographer’s assistant was critically wounded in the stomach and chest, the newspaper reported on its website. The victim was taken to a nearby hospital.