Molenbeek counter-terrorism operation
Counter-terrorism police conduct searches on rue Delaunoy (Delaunoystraat) in Molenbeek on January 14, 2017 in a major operationAFP/Getty Images

The Molenbeek district of Brussels was in lockdown tonight (14 January) as a major anti-terrorism operation was underway.

Four searches were conducted and three people were detained in the raids, the Brussels prosecutor's office confirmed.

"Several raids are being carried out as part of an investigation into terrorist activities," spokeswoman Céline Praille told RTL radio.

Ine Van Wymersch, also a spokeswoman for the prosecutor's office, later confirmed the raids had concluded, leading to three arrests. "The operation has ended. Nothing was found, no weapons, no explosives."

The three suspects will be questioned on Sunday (15 January) The Telegraph reports.

Large areas were cordoned off as the counter-terrorism squad moved into the area and a police helicopter was spotted flying overhead. It was reported that the army were also deployed during the raids by SWAT teams.

Images of masked policemen and armoured cars patrolling the streets have been shared on social media.

Historian Pieter Van Ostaeyen tweeted: "#Molenbeek Brussels 4 or more houses searched by police forces. Increased presence of military and police reported #Belgium"

Dubbed the 'jihadi capital of Europe' Molenbeek is known to be a hub for ISIS sympathisers and has been linked to several major terrorist incidents in recent years.

The district was home to Salah Abdeslam, the mastermind behind the 2015 Paris attacks which killed 130 people. Today's operation was centred around Rue Delaunoy, the street where Abdeslam was arrested.

Perpetrators of the 2004 Madrid train bombings, the Brussels Airport attack on March 22 which left 32 people dead and an attack in on a Jewish museum in the Belgian capital have also resided in Molenbeek.

Belgian authorities have been on high alert following the spate of suicide bombings.