Interpol announced that 25 people had been arrested on Tuesday as part of its "Operation Unmask" sting, targeting members of the hacking group Anonymous on accusations of defacing government and company websites.

"Operation Unmask was launched in mid-February following a series of coordinated cyber-attacks originating from Argentina, Chile, Colombia and Spain," said Interpol, based in the French city of Lyon.

In connection with the arrests, the statement listed attacks on the websites of the Colombian Ministry of Defense and presidency, as well as Chile's Endesa electricity company and the National Library of Chile, among others.

Some 250 items of computer equipment and cellular phones were seized in raids on 40 premises in 15 cities, the statement said.

'Fangs on party leaders'

Spanish police accused suspects of tampering with political party websites and defacing them, for example by putting fangs on images of party leaders. Spanish companies were also targets, the police said.

"These cyber attacks were sometimes individual actions but they were supported by many people who joined forces, and knowledge, to commit them," Spanish police said via the Interior Ministry. "Those arrested ... had a high level of knowledge of information technology."

Greek police arrested an 18-year-old last week - and identified two more suspects - accused of a hacking attack on the country's justice ministry. All three claimed to be part of the activist network.

Earlier this month, WikiLeaks began publishing more than 5 million emails from the global security analysis company Stratfor; the mails were believed to have come from Anonymous supporters.

The loosely-organized Anonymous group is perhaps best known for its support of the whistle-blowing website WikiLeaks, and has in the past hacked into government and corporate websites including Mastercard, Visa, the CIA and the FBI.

rc/msh (AFP, AP, Reuters)