Police in Europe and South America have arrested 25 alleged members of the "Anonymous" hacking group, Interpol said, amid a suspected attack on its own website by the group's supporters.

The arrests include four people in Spain, ten in Argentina, six in Chile and five in Colombia as part of a worldwide sweep carried out as part of Interpol operation "Exposure."

After Interpol announced the attacks, its website failed to load, a fact acknowledged by Anonymous on Twitter with the message interpol.int DOWN.

The Spanish police website also failed to load after it announced police had arrested four people in the country as part of the international action

Spanish police said the four suspects were accused of carrying out denial of service attacks, defacing the websites of political parties, institutions and companies, as well as publishing personal information relating to high-profile figures.

One of those arrested was a 16-year-old girl, who was allegedly part of international "sector 404," a hacking group which is believed to be linked to the attacks claimed by Anonymous. Police said the girl had been released to the custody of her parents.

Two of the others had been detained, while the third was released on bail, police said.