At least two people were stabbed on Friday near the former offices of the Charlie Hebdo satirical magazine in Paris that was attacked by Islamist militants over five years ago, in an incident anti-terrorism police were investigating.

Paris police said one person had been arrested. France Info radio said a second suspect was also in custody.

Prime Minister Jean Castex had earlier said four people had been stabbed, but a police source later told Reuters the number of people wounded was two, one of them seriously.

“I was in my office. I heard screams in the road. I looked out of the window and saw a woman who was lying on the floor and had taken a whack in the face from what was possibly a machete,” a witness told Europe 1 radio.

“I saw a second neighbour on the floor and I went to help.”

Paris police said one person had been arrested near the Bastille opera house. Europe 1 quoted police officials as saying the suspect was 18 and known to security services.

One police source said a machete had been found at the scene. Another police sources said a meat cleaver had been found there.

The national anti-terrorism prosecutor’s office said it was investigating the case.

TRIAL UNDER WAY

Fourteen people went on trial in Paris on September 2, accused of being accomplices in the attack on the Charlie Hebdo offices in January 2015 that killed 12 people.

The court heard that they had sought to avenge the Prophet Mohammad, nearly a decade after the weekly published cartoons mocking him.

Police moved Charlie Hebdo’s head of Human Resources from her home this week after threats against her life.

On Friday, TV footage showed ambulances, fire trucks and police cordoning off the area around Charlie Hebdo’s former offices.

Local authorities asked people to avoid the area and said a police operation was under way in a northeastern district of Paris. Deputy mayor Emmanuel Gregoire tweeted that police were hunting a “potentially dangerous” individual.

The Paris metro closed lines in the area and school children were initially kept inside in an area around the attack, a city hall official said.

France has experienced a wave of attacks by Islamist militants in recent years.

Bombings and shootings in November 2015 at the Bataclan theatre and other sites around Paris killed 130 people, and in July 2016 an Islamist militant drove a truck through a crowd celebrating Bastille Day in Nice, killing 86.