A man armed with a knife killed a teacher and injured several other people at a school in northern France on Friday, according to officials, who were treating the episode as a terrorist attack.
The stabbing took place at a public high school in Arras, a town of about 42,000 that is roughly 25 miles southwest of Lille, near the Belgian border. President Emmanuel Macron’s office said he was heading to the scene, and lawmakers in the lower house of Parliament suspended their work in solidarity with the victims.
Gérald Darmanin, the French interior minister, said that a suspect had been arrested and was in police custody.
France’s national antiterrorism prosecutor’s office said in a statement that it had opened an investigation, but it did not provide details about the suspect or his motivations.
French officials did not immediately identify the victims or provide details about how the attack unfolded.
While attacks on schools are rare in France, this stabbing struck a raw nerve in the country. It occurred almost three years to the day after Samuel Paty, a 47-year-old history teacher who showed caricatures of the Prophet Muhammad in class to illustrate free speech, was beheaded by an Islamist fanatic.
More recently, a Spanish language teacher at a high school in the southwest of the country was stabbed and killed by a 16-year-old student, although terrorism was ruled out in that case.
France was struck by large-scale Islamist terrorist attacks in 2015 and 2016, followed by a string of smaller but still deadly shootings and stabbings in subsequent years, often carried out by lone assailants.
The country remains on high alert, and the authorities have said that the police and intelligence services regularly foil plots. Mr. Darmanin told the newspaper Ouest-France last month that the authorities had thwarted 42 terrorist attacks since 2017.
This is a developing story. Please check back for updates.