The French government is promising to hunt down hackers who knocked out channels belonging to a French TV station and posted material on its social media feeds.
In one message, the attackers, who say they are supporters of ISIL, protest against French military action in Iraq.
The government has described the cyber assault on TV5 Monde or TV5 World, as “vile and cowardly.”
“We are facing determined terrorists and we are determined to combat them. The means they use require us to adapt our approach permanently. And that’s what we are doing,” said Bernard Cazeneuve, French Interior Minister.
Laurent Fabius, French Foreign Minister, added: “The priority must be cyber security and cyber defence. Preserving freedom of course, but cyber security and cyber defence are the options we’re mainly pursuing.”
TV5, which broadcasts news and entertainment programmes in French around the world, says the attack caused 11 channels to go off air temporarily.
France is part of an international coalition carrying out strikes against ISIL militants in Iraq.