French authorities have detained the father and brother of one of the attackers who carried out the series of coordinated suicide missions in Paris, a former French official confirmed to NBC News.
The father was taken into custody in Romily-sur-Seine, southeast of the center of Paris, and the brother was taken into custody in Bondoufle, south of the capital, according to the French newspaper Le Figaro.
The official said they are related to an attacker identified only as Ismail M.
French authorities have been searching for anyone who may have been involved in the series of suicide bombings and shootings that targeted a stadium, cafes and a concert hall. The attacks killed 129 people and wounded 352 more, French officials said Saturday.
French media identified another attacker as Abbdul Akbak B. A former French official confirmed to NBC News that the partial identity is correct.
The seven attackers are dead, six of them by suicide bombings, officials said.
Five people have been arrested in Belgium in connection with the attacks, Molenbeek mayor Françoise Schepmans said Sunday. Three of those arrests had previously been confirmed.
"We can consider this means they have a network," she said.
ISIS has claimed responsibility for the attacks. French President Francois Hollande has vowed a "merciless" response. Hollande declared a state of emergency and closed the nation's borders after the terror attacks.