The League for Human Rights filed a complaint with the Flanders region's Agency for Interior on Friday over a new Antwerp police approach allowing the preventive arrest and detention of known troublemakers for up to 12 hours, even when they are not committing an offense or causing a disturbance at the time.

According to an internal police memo reviewed by Gazet van Antwerpen, officers can administratively arrest individuals identified as known troublemakers and detain them for up to 12 hours if they encounter them during checks, without requiring evidence of an offense or an ongoing disturbance.

The Antwerp police confirmed the approach to Belgian public broadcaster VRT, saying the measure aims to protect public order and improve the quality of life in the city while encouraging those affected to accept assistance.

However, the League for Human Rights has questioned the legality of the measure, arguing that a person’s reputation or inclusion on a police list cannot, by itself, justify the deprivation of liberty.

"Administratively detaining someone for 12 hours solely because they have been labeled and are on a list is, in our opinion, absolutely unlawful," League chairwoman Kati Verstrepen told VRT.

Antwerp Mayor Els van Doesburg has defended the approach, saying it targets people who allegedly accost passersby aggressively while seeking money or drugs, establish sleeping places in public areas and struggle with problems including alcohol abuse and severe drug addiction.

Peter Mertens, general secretary of the Workers' Party of Belgium, criticized the plan in a post on US social media company X, describing it as "unlawful" and "dangerous." "You can't just throw people into a cell without any reason. This sets a dangerous precedent and opens the door to abuse," Mertens wrote.