Three men detained for questioning last night after an anti-terror raid in the Brussels district of Molenbeek have been released without charge, Belgian prosecutors said.
Prosecutors said yesterday that several houses had been searched in relation to an anti-terror investigation but that nothing was found.
They did not give any details about the case.
The Molenbeek area was home to several of those who took part in the deadly November 2015 attacks in Paris and the suicide bombings of Brussels airport and the metro in March 2016.
The authorities stepped up security after the killings and there have been periodic police raids and arrests since then as the investigations have continued.