The cyber attacks launched by Anonymous targeted companies that had stopped working with WikiLeaks [EPA]

Five people have been arrested in Britain in relation to a number of cyber attacks carried out by a group called Anonymous, which hacked company websites in apparent support for WikiLeaks, the whistleblower website.

Three teenage boys and two men were held following a series of dawn raids on Thursday, and detained on suspicion of breaking the Computer Misuse Act.

"The five males aged 15, 16, 19, 20 and 26 are being held after a series of coordinated arrests at residential addresses," a statement from the London Metropolitan police said.

"The arrests are in relation to recent and ongoing 'distributed denial of service' attacks (DDoS) by an online group calling themselves 'Anonymous'."

The action is part of an international probe into Anonymous - a loose-knit group of online activists who are said to be responsible for attacking and temporarily shutting down Visa Europe, PayPal, Mastercard and Amazon sites last year.

The cyber attacks came as a response to those companies severing links with WikiLeaks, which released thousands of US diplomatic cables and secret war logs from Iraq and Afghanistan.

WikiLeaks said it did not sanction retaliatory attacks by Anonymous.

A typical DDoS attack sees a large number of computers commanded to simultaneously visit a website, overwhelming its servers, slowing service or knocking it offline completely.

People convicted of computer misuse offenses in the UK face up to 10 years in jail and a $7,984 fine.

Source: Agencies