LONDON — A group of American hackers, New World Hacking, has claimed responsibility for the cyber attack on the BBC website, which took it down for three hours on New Year’s Eve.

The group claims to target those supporting Islamic State, and said that the BBC attack was merely “a test of its capabilities,” according to the BBC’s technology correspondent Rory Cellan-Jones.

In a tweet to Cellan-Jones, the group said: “We are based in the U.S., but we strive to take down Isis (Islamic State) affiliated websites, also Isis members.”

It added: “We realize sometimes what we do is not always the right choice, but without cyber hackers… who is there to fight off online terrorists?

“The reason we really targeted (the) BBC is because we wanted to see our actual server power.”

The group said it hadn’t planned to take the BBC site down for “multiple hours.”

A member of the group — known as Ownz — told BBC reporter Leo Kelion that New World Hacking consisted of 12 people, eight men and four women. They formed the group in 2012. Their other activities have included a cyber attack on the Ku Klux Klan, and the #OpParis campaign to close IS social media accounts following the Paris terror attacks.

A BBC source has admitted that the cause of the website’s crash was a “distributed denial of service” attack, where the site is bombarded by traffic until it falls over. Officially, the BBC has not said that it was the victim of a cyber attack, preferring to blame its problems on technical difficulties.