Belgian police officers in the Brussels district of Molenbeek
Belgian police officers in the Brussels district of MolenbeekReuters

Belgian police on Saturday night detained three people for questioning after carrying out house searches in Brussels that were related to an anti-terrorism investigation, Reuters reports.

The house searches were carried out in the Brussels district of Molenbeek, which has a high concentration of Muslim immigrants.

Several terrorists who carried out attacks in Europe came from Molenbeek, including Abdelhamid Abaaoud, who was the mastermind behind the Islamic State (ISIS) attacks in Paris in November of 2015.

"The searches were carried out as part of an investigation by Brussels prosecutors," a spokeswoman for Brussels prosecutors said, according to Reuters.

"While nothing was found, three people were taken in for questioning," she added.

Belgian police have been on high alert ever since the Paris attacks and the attacks in Brussels which followed.

Security forces regularly conduct raids and arrests in Molenbeek.