On Tuesday, the Anonymous group bombarded dozens of government websites with access requests, causing them to temporarily slow down. The hackers also targeted a number of private websites, including that of Israeli singer Ivri Lider's.
In some instances, the hackers replaced websites' start pages with pictures of a Muslim holy site in Jerusalem and the Sunni militant group Islamic State's flags, and posted a message in Arabic and English signed by "AnonGhost."
"Greetings world we are AnonGhost. We are always here to punish you! Because we are the voice of Palestine and we will not remain silent," the web message read.
People claiming to represent Anonymous have regularly carried out cyber attacks against Israel every year on April 7 since 2013. At the time, the hackers began their campaign, calling it "OpIsrael," on the eve of Israel's annual Holocaust Remembrance Day. The date of this service varies each year by the Gregorian calendar, however the hackers seem to have stuck to their April 7 appointment. Last year's attacks also caused minimal disruption.
In a separate video message on Tuesday, Anonymous said it was attacking Israeli websites in response to the Jewish state's "crimes in the Palestinian territories," including last summer's bombardment of Gaza.
The pro-Palestinian hacking collective had earlier said it would carry out an "electronic Holocaust" against Israel that would topple the Israeli government, banks and public institutions. Israel's cyber experts, however, said the group failed to cause any major disruption.
Israel's national cyber bureau said it had instructed the "relevant authorities" to boost cyber defense ahead of Tuesday's attacks.
shs/msh (dpa, AP)