"In Antwerp we actively control 557 people," De Wever said on-air of the Een broadcaster, adding that 189 people were considered to be "really dangerous."
In April, local media reported, citing the figures of the Interior Ministry, that nearly 19,000 people were on Belgium's authorities' terror suspect list, up tenfold compared to 2010. Over 2,200 of those people were considered to be radicalized substantially enough to conduct terrorist attacks.
The most recent attack took place on Tuesday, when a blast hit a Brussels train station. The suspect who carried out a small explosion was subsequently killed by security forces. On Wednesday, Belgian Interior Minister Jan Jambon said the attacker had a powerful explosive device with him and planned to carry out a bigger explosion, but failed to do so.
Belgium has become one of Europe's most terror-prone countries over recent years amid a larger wave of terrorist attacks across the continent. The country's security services have been investigating several cases related to last year’s terror attacks in Paris and this spring's Brussels bombings, as well as other foiled terror plots within its borders. Belgian authorities have kept a high terror alert level since March of last year.