Belgian police were investigating in 14 homes as part of terrorism investigationsthe federal prosecutor’s office announced today, adding that seven people have been brought in for questioning.

“These individuals were considered suspicious, among other things, of preparing a terrorist attack. The specific targets of the attack have not yet been determined,” the police statement underlines.

A judge will decide later whether to press charges against them.

House searches took place in the cities of Antwerp, Liège and Ghent, among others, and in the Brussels area.

The prosecutor’s office did not immediately comment on whether the terrorist attack plans were related to the Paris Olympics, which begin on Friday.

The anti-terrorism prosecutor’s office in Paris did not respond when asked whether French authorities were involved in the Belgian investigations.

The perpetrators of terrorist attacks in Paris in 2015in which 130 people were killed and 368 injured, largely planned and coordinated their attacks from Belgium, with some of the perpetrators being Belgian nationals or residents.

In 2016, Brussels airport bombings they killed 34 people and injured 340. Among those convicted of the attacks was Salah Abdeslam, who was also the prime suspect in the Paris attacks trial.