Belgian police on Thursday detained seven people suspected of planning what authorities called a terrorist attack. 

The Federal Prosecutor's Office said the individuals were "suspected of participating in the activities of a terrorist group, of financing terrorism and of preparing a terrorist attack."

"The specific targets of the attack had not yet been determined," it added.

The individuals were questioned, and a judge will determine whether they would remain in custody.

Police raid homes across Belgium

The detentions came as police raided 14 homes across Belgium as part of the terror investigation.

The homes were located in the Brussels region as well as the cities of Antwerp, Liege, and Ghent.

The prosecutor's office did not provide further details about any potential affiliation with specific groups.

The investigation comes a day before the opening ceremony for the 2024 Olympics in Paris. Belgian and French authorities did not immediately comment on whether there was any link to the Games.

A Brussels-based cell of the "Islamic State" group murdered 131 people in Paris in November 2015, while 32 people were killed in Brussels in March 2016.

zc/sms (Reuters, AFP, dpa)