A fourth suspect was charged on Monday in Belgium over the Paris terror attacks, the Belgian federal prosecutor announced.

The man was arrested on Sunday night in a series of co-ordinated police raids around Brussels and Charleroi and charged with participating in the activities of a terrorist group and participating in the Paris terrorist attack, the prosecutor said.

Another 15 people arrested on Sunday were freed without charge. The prosecutor said: "It is not uncommon, during large-scale search operations, to bring in several people merely for thorough questioning or to clarify why they were found on the searched premises."

Five more people were arrested in Brussels and the south-eastern Belgian city of Liege on Monday. The prosecutor's statement added that two of them have been released. Further inquiries are taking place for the other three.

No further information will be given about the identity of the persons arrested, the statement added.

The other three suspects charged by Belgian authorities are 39-year-old Abraimi Lazez, 21-year-old Hamza Attou and 27-year-old Mohammed Amri.

Lazez was arrested in his car in the Brussels district of Laeken last Thursday. Belgian public broadcaster RTBF said Attou and Amri both admitted being in the car that drove prime suspect Salah Abdeslam back to Brussels after the Paris attacks on Nov. 13.

Abdeslam remains at large.