An image grab taken on April 9, 2015 from a video on TV5Monde Facebook account shows a message that appeared on French television network TV5Monde's facebook account while it was hacked by individuals claiming to belong to the Islamic State group. The hackers posted documents on TV5Monde's Facebook page purporting to be the identity cards and CVs of relatives of French soldiers involved in anti-IS operations, along with threats against the troops.[Photo/CFP]

PARIS - A French television network has been hacked by people claiming allegiance to the Islamic State group, the channel's director said Thursday.

The hackers briefly cut transmission of 11 channels belonging to TV5 Monde and took over its websites and social media accounts. The channel's director, Yves Bigot, said the attack was continuing Thursday morning. He told RTL radio that the network has restored its signal but can only broadcast recorded programs.

He said he was shaken when he saw 11 channels with a black screen "and when we discovered the sense of the message appearing on our social media and our websites, it both allowed us to understand what was happening and obviously worried us."

The message on the TV5 Monde website read in part "I am IS" with a banner by a group that called itself Cybercaliphate. That was replaced later Thursday by a simple message saying that it was undergoing maintenance.

Prime Minister Manuel Valls, on his Twitter account, called the attack "an unacceptable insult to freedom of information and expression'" and expressed his support for the editorial staff. Interior Minister Bernard Cazeneuve tweeted that he and the ministers of culture and foreign affairs were visiting the channel's offices.

The Islamic extremist group has claimed complex hackings before, but the seizure of the French network appeared to be a new step in its information warfare tactics.