The daily La Dernière Heure reported that the army bomb disposal squad also attended the scene. In all 82 residents were forced to leave their homes for three full hours and were taken to a local community centre.
Police sources stress that the entire operation went smoothly.
La Dernière Heure reports that police raided a house on information received from France.
A police spokesman would not be drawn on whether or not this was an operation linked to terrorism: "We have to consider all elements. Several different police services are involved. We're not commenting on rumour."
The federal prosecutor was kept abreast of developments.
Police and prosecutor are expected to provide more information this morning.