PARIS — At least four police officers were killed on Thursday at Paris Police Headquarters by an employee with a knife, according to a French union official.
The unidentified attacker was shot and killed by an officer, said the police union official, Loïc Travers of the Alliance Police Nationale union. He said the assailant appeared to have started attacking officers in his office before moving to other areas in the headquarters.
“The motive is not yet known,” Mr. Travers added.
The headquarters of the Paris police prefecture, near Notre Dame cathedral, did not immediately respond to requests for comment.
Mr. Travers told reporters that the suspect was an administrative employee who had worked at Police Headquarters for more than 20 years. His latest job was with the Paris police’s intelligence unit, Mr. Travers said, adding that the suspect had “posed strictly no problem” in the past.
The assault is likely to rekindle security concerns in the French capital, where in 2015 terrorists attacked the satirical newspaper Charlie Hebdo, killing 12 people including a police officer, and a series of coordinated terrorist attacks in a nighttime rampage across the city later that year left more than 100 dead.
Anne Hidalgo, the mayor of Paris, said in a post on Twitter on Thursday that “Paris is mourning its own” after a “horrifying attack.”
The Police Headquarters were closed and the surrounding area around were cordoned off after the attack. A nearby metro station was also closed. The Paris prosecutor was on the scene, his office said, giving no further information.
President Emmanuel Macron, along with the prime minister, the interior minister and the Paris police chief, went to Police Headquarters to express his “support and solidarity” with the staff, his office said.
The attack came a day after tens of thousands of police officers demonstrated in Paris in anger over what they said were bad working conditions and a lack of public respect, and over several police suicides this year.
Pauline Rossignol, a 28-year-old human resource officer at the police préfecture, had been on her lunch break when the attack occurred. She said she had had enough of “tragedies” affecting her colleagues.
“It’s going to be one more minute of silence, after so many,” Ms. Rossignol said as she sat on the stairs by the banks of the Seine River, unable to go back to her office.
“There have been too many suicides of police officers, too many of them who died in terrorist attacks,” she added. “Police forces suffer a lot; we are a target.”
The number and scope of terrorist attacks in France has gradually decreased since the wave of deadly violence in 2015 and 2016, but police officers have still been targets.
In 2016, an Islamic State assailant fatally stabbed a police officer and his companion at their home in a town about 35 miles west of Paris, while their child was present. In 2017, a veteran police officer, Xavier Jugelé, was shot and killed by a gunman on the Champs-Élysées.