At least four officers have died in a knife attack at the police headquarters in Paris, the BBC reports. The attacker, who union officials identified as a police administrator at the central office, has been shot dead by police. The attack reportedly began inside an office and then moved throughout the compound that’s across the street from Notre Dame Cathedral early Thursday afternoon. French President Emmanuel Macron, Interior Minister Christophe Castaner, and Paris’s chief prosecutor are reported to be at the scene. The area in the île de la Cité—in the middle of Paris—has been sealed off. Union official Loic Travers said the employee said to be responsible for the violence had never been known to pose any problems before the attack.