French police have identified one of the assailants in the coordinated attacks in Paris as Ismael Omar Mostefai, a 29-year- old French national, and seven of his relatives are being questioned, sources and French media said on Sunday.
Authorities had a dossier on Mostefai that marked him as a potential Islamist militant. He also had previous arrest records and had been sentenced eight times for petty crimes, according to French newspaper Le Monde. Mostefai was one of the gunmen who blew himself up in a Paris concert hall where most of the 129 deaths from the attacks late on Friday took place.
His father, a brother and five other people are being held for questioning, several French media reported on Sunday, as the hunt continued for others involved in the shootings.
The reports said searches were also being conducted in the relatives' homes in the northeastern Aube region and in Essonne, south of Paris.
Father-of-one Mostefai was born in Courcouronnes, a southern suburb of Paris and lived in Chartres, southwest of the capital. He is suspected to have stayed in Syria between 2013 and 2014, Le Monde reported.
A source close to the investigation also confirmed media reports that a vehicle, a black Seat, used in the attacks was found with some arms onboard in Montreuil, a suburb in the east of Paris. Paris prosecutor Francois Molins said on Saturday that the Seat had been used in the attacks.
A Frenchman who thought to have hired another car used in the attacks was stopped at the Belgian border on Saturday morning, along with two other people, Molins said.
Molins said investigated believed three coordinated teams had carried out the wave of attacks across Paris. They were the worst in Europe since the Madrid train bombings of 2004, in which Islamists killed 191 people.
Friday's attacks were described as an "act of war" by President François Hollande.
The bloodshed came as France, a founder member of the U.S.-led coalition waging air strikes against Islamic State in Iraq and Syria, was already on high alert for terrorist attacks.