A weekend cyberattack campaign has targeted Israeli government websites but failed to cause serious disruption, officials say.

Yitzhak Ben Yisrael, of the government's National Cyber Bureau, said on Sunday that hackers had mostly failed to shut down key sites.

"So far it is as was expected, there is hardly any real damage," Ben Yisrael said. "Anonymous doesn't have the skills to damage the country's vital infrastructure. And if that was its intention, then it wouldn't have announced the attack of time. It wants to create noise in the media about issues that are close to its heart,'' he said.

The cyber attacks followed a warning from the hacker group Anonymous, which said it would launch a massive attack on Israeli sites in an "operation" called #OpIsrael.

"You have shown that you do not respect international law," said the group in a video released online addressing the Israeli government.

"This is why that on April 7, elite cyber-squadrons from around the world have decided to unite in solidarity with the Palestinian people against Israel as one entity to disrupt and erase Israel from cyberspace," it added.

Israel's Bureau of Statistics was down early on Sunday but it was unclear if it had been hacked.

Media reports also said the sites of the Defence and Education Ministry as well as banks had come under attack the night before but were mostly repelled.

Haaretz newspaper said almost 19,000 Israeli Facebook accounts had been attacked by hackers affiliated with Anonymous.

Last November, hackers broke into Israeli websites during fighting in Gaza but failed to cause serious disruption, according to AP news agency.

Tweets about "#OpIsrael"