Three people are detained, suspected of terror-related crimes in Belgium, following extensive police raids across the country on Thursday when seven people were arrested.
The three who are now being held in custody are accused of preparing for a terrorist attack. They are suspected of collaborating with an IS-affiliated group.
There is no evidence of any connection to the OS in Paris, whose opening ceremony takes place on Friday evening.
Belgium was shaken in 2016 by suicide attacks at Zaventem airport and in the Brussels metro, where 32 people were killed and hundreds injured.
They came a year after the attacks in Paris where 130 people were killed.