Hackers Anonymous 'disable extremist website'
Hacking group Anonymous has claimed responsibility for disabling an extremist website based in France.
A post on Twitter said "Tango Down" and included a link to a site which has been linked to extremists.
Anonymous "declared war" on jihadist websites on Friday after the Paris attacks.
The group posted a video saying it would target extreme social media accounts as part of efforts to protect freedom of speech.
The warning came in the same video as a tribute to the victims of the attack on French satire magazine Charlie Hebdo.
On Sunday, more than a million people marched through the streets of Paris in solidarity, as well as in London and other cities around the world.
A Belgian part of the hacking group said in the message: "We are declaring war against you, the terrorists."
Since it was posted on 8 January, more than 6.5 million people have watched the clip, which shows a figure wearing the group's signature Guy Fawkes mask.
In an earlier message posted on forum site Pastebin, the group addressed the "enemies of freedom of expression", and warned extremists: "Expect a massive frontal reaction from us because the struggle for the defence of those freedoms is the foundation of our movement."
The message signed off by saying: "We will not forget. We will not forgive. Dread us."
The nature and type of attack on the website is not yet known, but in the past Anonymous has used Distributed Denial of Service (DDoS) as a way of bringing down websites by flooding them with traffic until they go offline.
The website targeted by Anonymous now redirects to an internet search engine, DuckDuckGo.
DDoS attacks were identified as the source of the problems with the PlayStation Network, which went down over Christmas leaving gamers unable to get online.
Anonymous is a group made up of activists and hackers claiming to defend and protect democracy.
They've previously made threats against the BBC, while hackers linked to the group also threatened to release sex tape images which they claimed were of Iggy Azalea.
The group has carried out denial of service attacks on websites belonging to governments, as well as religious and corporate organisations.
Twelve people, including eight journalists and the magazine's editor, were murdered in last Wednesday's gun rampage.
On Friday, the two brothers suspected of being behind the shootings were killed in an assault at a warehouse where they had held a hostage north of Paris.
The hostage was freed unhurt.
At the same time, anti-terror forces stormed a Jewish supermarket in eastern Paris where several hostages were held by another gunman.
Four hostages at the supermarket and one captor were killed.
It's thought the three hostage-takers were connected and that the supermarket captor was also behind the shooting of a police woman on Thursday.
Police are still looking for a 26-year-old woman, Hayat Boumeddiene, over that attack.