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

The house searches were carried out in the Brussels district of Molenbeek, which gained international attention when locals with links to Syria took part in the November 2015 attacks that killed 130 people in Paris.

"The searches were carried out as part of an investigation by Brussels prosecutors," a spokeswoman for Brussels prosecutors said. "While nothing was found, three people were taken in for questioning."

The area where the searches took place was closed off to traffic as special police forces with machine guns moved in, a Reuters journalist said.