Explosion occurred Sunday evening in front of the door of Russian nationals. The hypothesis of a settling of scores is now being considered by investigators.
The doors of the two apartments have been replaced by armored doors. Two hooded men were seen fleeing after the incident. On site, they also found a black box measuring approximately 40 cm and the remains of a tea light which may have been used to make the device. The Val-d'Oise PJ is investigating the explosion which occurred in Cergy.