( CNN ) -- Several Israeli government websites appeared to crash as anti-Israeli hackers launched cyberattacks Sunday , but Israeli hackers also claimed their own victory . The website that promoted the `` OpIsrael '' cyberattacks was itself hacked . Instead of anti-Israeli messages , it was playing Israel 's national anthem , `` Hatikvah . '' A group calling itself Anonymous Arab said in a YouTube video posted last week its cyberattack plan would come in three phases . `` Step one will be initiated after the release of this message and will be comprised of systematically removing the Zionist entity from the Internet , '' a speaker said in Arabic . The video shows a masked person appearing to read . `` Step two , we will discover your future plans and show your crimes against humanity to the whole world , '' the speaker said . `` `` And as for step three , well think of this one as a present from Anonymous to you . '' It concluded : `` We are Anonymous . We are legion . We do not forgive . Expect us . '' The websites for Israel 's Knesset and elections agency appeared to be down Sunday . Yitzhak Ben Yisrael , the head of the Israel'sÂ National Cyber Directorate , downplayed the effects of the cyberattacks in an interview Sunday with Israel Radio . `` As was expected , up until now there has been no real damage , and the hackers do n't have the tools to cause damage to the vital infrastructures , '' Yisrael said . CNN 's Michael Schwarz and Amir Ahmed contributed to this report .
Websites for Israel 's Knesset and intelligence agency appeared to be down Sunday . Hamas ' own website was itself hacked ; it contains Israel 's national anthem . Hackers can do ` ` no real damage , '' Israeli cyberchief ##s . Group called Anonymous Arab announced attack early last night .