A screengrab from the original threat, posted on YouTube

The shadowy organisation had threatened a 'massive' attack in retribution to the Paris massacre

Hackers with Anonymous claim to have brought down a pro-jihadist website in retaliation for the Charlie Hebdo attacks last week.

On Friday a Belgium offshoot of the hacktivist group posted a video on Youtube “declaring war” against “al-Qaeda, Islamic State and other terrorists”, and promised a “massive” attack in retribution in a separate post on pastebin.

Late Saturday the group appeared to boast of its success, posting on Twitter account @OpCharlieHebdo: “#TangoDown” and the name of a French website associated with extremists, accompanied by a screen-shot of the site – which now redirects to search engine DuckDuckGo.

The website Ansar-alhaqq.net, briefly up and running yesterday, remains unavailable today.

Since its posting on Friday the original French video, which threatened an attack under the name #OpCharlieHebdo, has been viewed more than four million times, with over 21,000 likes and roughly 1,600 dislikes.

Anonymous have become known for a series of well-executed public attacks on corporations, religious and governmental bodies.

The organisation remains shadowy, with a loose and decentralised command structure that claims to “operates on ideas rather than directives,” according to a Boston University Law review paper.

Yesterday millions took to the streets across Europe yesterday to remember the 17 people killed in the last week's terror attacks.