The Belgian authorities have released the brother of one of the bombers in the Paris attacks.
A lawyer for Mohamed Abdeslam told the BBC that he had been freed without being charged.
Mr Abdeslam's brother Brahim was one of the gunmen who blew themselves up at the Bataclan theatre, while his other brother, Salah, is considered a key suspect in the attacks by French police.
Besides, the authorities released four more suspects arrested in Brussels over the weekend in connection with the Paris attacks.
A judge still has to decide whether to continue holding the other two suspects.
Abdelhamid Abaaoud was pictured in Islamic State's online magazine, Dabiq
The major operation by Belgian police in Brussels which was aimed at finding Salah Abdeslam, one of the key suspects in the Paris attacks, has finished, local mayor Francoise Schepmans tells Belgium's state broadcaster RTBF.
Reports that Abdeslam is suspected of having masterminded the Paris attacks are unconfirmed "rumours", prosecutors in Belgium tell the Reuters news agency.
French officials earlier said they were investigating links between the attackers and Abdelhamid Abaaoud, a Belgian now based in Syria with the jihadist group Islamic State (IS).
Abaaoud has played an important role in planning attacks in Europe, officials believe.
