Earlier in the day, a similar letter was received by State Security, resulting in the quarantine of an employee who had come into contact with it.

During the operation, traffic was closed between Rue Royale and Avenue des Arts, with multiple police vans, fire trucks, and a civil protection unit deployed to the scene.

Additionally, two bomb alerts were reported in Brussels metro stations, with one occurring at Park station around 7:30 PM and another at Simonis station earlier in the day.

The police confirmed that negative results were found during searches for both bomb alerts, which facilitated the return to regular service at the affected metro stations.

On November 20, 2024, authorities in Brussels responded to two suspicious envelopes sent to the State Security and the office of the Minister of the Interior, prompting the establishment of a security perimeter.

In response to the incidents, police interventions were significant in central Brussels, particularly near Rue de la Loi where the envelopes were received.

One of the envelopes, which contained a suspicious powder, was found at the office of outgoing Interior Minister Annelies Verlinden; fortunately, no injuries were reported.

The Park station was eventually reopened after a thorough search by police and bomb detection dogs yielded negative results, allowing normal operations to resume.