what's not known is how mohammed bell khaid is linked if at all to the paris attacks where 130 people were killed. it is known though that the paris plot was planned in brussels, four months on questions remain about the intelligence failings leading up to the attack and belgium remains at the heart of the investigation. emma hayward, al jazeera, brussels. >> in france, authorities have arrested four people including one who may have been planning an attack on paris. al jazeera.'s jacky rowland has more, including informing about one suspect's checkered past. >> a 20-year-old frenchman of moroccan origin. he was arrested in 2012 as he was planning to board a flight ogo to syria. suspected of wanting to go and fight there. now, he is only just been released in from prison in october of last year in fact he was already being held under house arrest since the end of february as part of the state of emergency here in france. now, he was arrested as were three members of his ento your , french nationality but of turkish origin. no actual weaponry was seized, just computer material, usb key