Man Arrested After Attempting to Enter House of Councillors Office Building with Knife

Incident at the House of Councillors

On April 20, 2026, security personnel at the House of Councillors office building in Nagatacho, Tokyo, apprehended a man attempting to enter the facility while in possession of a bladed weapon. The incident occurred during standard security screening procedures at the building's entrance.

Details of the Arrest

According to reports from the Tokyo Metropolitan Police Department, the individual was stopped by security staff before he could gain access to the interior of the office complex. Upon inspection, a knife was discovered in his possession. The man was immediately detained by police officers stationed at the site. Key details regarding the incident include:

• Location: House of Councillors office building, Chiyoda Ward, Tokyo.
• Status: The suspect was arrested on the spot for violation of the Swords and Firearms Control Law.
• Casualties: No injuries were reported among staff, security personnel, or the public.

Ongoing Investigation

Authorities have launched an investigation into the suspect's background and his intent for attempting to enter the legislative office building. While the investigation is in its early stages, police are reviewing security footage and questioning the individual to determine if there was a specific motive. A police spokesperson stated, 'We are conducting a thorough investigation to determine the circumstances surrounding this incident and to ensure the continued security of government facilities.'

Security Measures in Nagatacho

The Nagatacho district, which houses the National Diet of Japan and various government office buildings, maintains high levels of security. Following the incident, security protocols at the House of Councillors office building remain in place, with authorities emphasizing that the situation was contained quickly without disruption to the legislative functions of the Diet.