A man wielding a knife killed at least four people and wounded several others at the Paris police headquarters on Thursday.

French media reported that a staff member, a 45-year-old man, carried out the attack with a ceramic knife in a part of the prefecture that is not open to the public.

"People were running everywhere, there was crying everywhere," said Emery Siamandi, an interpreter who was in the building when the attack happened.

"I heard a shot, I gathered it was inside," he told AFP News Agency. "Moments later, I saw police officers crying. They were in a panic."

Loic Travers, a union official, told the AFP that an officer shot and killed the attacker in the historic building near Notre Dame Cathedral.

There has been no official statement so far. The area in the center of Paris - has been sealed off.

The attack comes a day after police went on strike across France over increasing violence toward officers.

It happened at about 13:00 local time (11:00 GMT) in the courtyard of the building.

President Emmanuel Macron, Prime Minister Edouard Philippe and Interior Minister Christophe Castaner have all gone to the site.