ROME, May 17 (RAPSI) - Authorities in Italy have launched a major crackdown on the international hacker group Anonymous, which thus far has resulted in the arrest of four suspects, Rai New24 TV channel reported on Friday.

The suspects have been placed under house arrest and dozens of searches have been conducted.

The operation, nicknamed Tango Down, covered the entire country and was coordinated by the General Public Prosecutor's Office in Rome.

The four hackers that were arrested are responsible for attacks on the Italian government and parliament websites as well as the Vatican, investigators said.

Anonymous became known in late 2010 after it carried out a series of attacks on the websites of companies and organizations which fought the recently exposed WikiLeaks document archive and disclosure resource. They also attacked the websites of the PayPal, Visa and MasterСard payment systems.

Anonymous regularly attacks government and other official websites in many countries.