Hacker collective Annoymous is carrying out cyber attacks on ISIS, as it promised it would, in the wake of the terrorist atrocities in Paris last week.

The hacktivists claim to have taken down 6000 Twitter accounts associated with the terrorist group, while also releasing a guide to catching ISIS members.

The group has also begun releasing the details of thousands of social media accounts and other personal details of those alleged to be involved in the terrorist group.

In a video on Monday a masked Anonymous member warned ISIS it should "expect massive cyber attacks". Accounts associated with the group began tweeting account details of ISIS members.

Business Insider reports that the terrorist group has hit back in the escalating cyber war. ISIS reportedly posted a message on an encrypted messaging service that said: "The #Anonymous hackers threatened in new video release that they will carry out a major hack operation on the Islamic state (idiots),"

Annonymous is known for taking on its enemies via DDoS attacks and other hacking techniques. It ran a similar campaign against terrorist groups in the wake of the attacks in France on the satirical magazine Charlie Hebdo and a Jewish supermarket in January.