Hacking group Anonymous has released a video declaring war against the Islamic State group following Tuesday's attacks in Brussels. In this photo, a person claiming to speak for activist hacker group Anonymous is seen in a video circulated online, Nov. 1, 2013. Getty Images/ROSLAN RAHMAN/AFP

Anonymous, the loose collective of online activists, released a video Wednesday threatening to attack the Islamic State group in the wake of Tuesday’s Brussels attacks. At least 34 people were killed and several injured in suicide bombings and explosions in the airport and metro station of the Belgian capital.

In the video, Anonymous said that it will begin the so-called “OpBrussels” by hacking ISIS websites, shutting down “thousands” of ISIS Twitter accounts and “stealing their Bitcoins” in response to the militant group’s attacks in Brussels. On Tuesday, ISIS claimed responsibility for the attacks in Brussels.

"Our freedom is once again under attack… This cannot continue,” a computerized voice was heard saying in the latest Anonymous video. "To the supporters of Daesh (acronym for ISIS), we will track you down, we will find you, we are everywhere and we are more than you can imagine… When they killed innocent civilians in Belgium, they hit everybody in Europe. We have to fight back.”

The hacking group had released a similar video following the Nov. 13 attacks in Paris that were claimed by ISIS. In the video, which was released on the day of the Paris attacks, Anonymous vowed to hunt down those responsible and expose them, calling Operation Paris (or OpParis) "the biggest operation ever" against the extremist group.

"Following the attacks in Paris last November, we have fought daily against terrorism and we have silenced thousands of Twitter accounts directly linked to ISIS,” Anonymous said in the latest video. "We severely punish Daesh on the dark net, hacked their electronic portfolio and stolen money from the terrorists."

The Brussels attacks came just days after Belgian police captured the prime suspect of the Paris attacks.

Days after OpParis was launched, various groups within Anonymous claimed to have identified tens of thousands of Twitter accounts and taken them offline, as well as targeting some ISIS-related websites, including one that it claimed was a recruitment site for the terrorists, which is now permanently offline.

Anonymous, which had launched the "ISIS Trolling Day" in December aimed at mocking the extremist group by posting unflattering images on social media to undermine its credibility, took a shot at ISIS in Wednesday’s video, saying: “We have laid siege to your propaganda websites, tested them with our cyber attacks, however we will not rest as long as terrorists continue their actions around the world. We will strike back against them.”

In November, Anonymous published a series of guides to help people to identify and attack websites and social media accounts of ISIS online.

Watch the video by Anonymous here.