More than 44 million hacking attempts have been made on Israeli government websites since Wednesday when Israel began its Gaza offensive, according to Israeli officials.

Finance minister Yuval Steinitz said just one hacking attempt was successful on a site he did not want to name, but added that it was up and running after 10 minutes of downtime.

Attempts on defence-related sites were the most numerous, according to his ministry, while 10m attempts were said to have been made on the site of Israel's president, 7m on the foreign ministry and 3m on the site of the Israeli prime minister, Benjamin Netanyahu.

A finance ministry spokesman told Reuters that while the attacks have come from around the world, most have been from Israel and the Palestinian territories.

"The ministry's computer division will continue to block the millions of cyber-attacks," said Steinitz, speaking ahead of the weekly cabinet meeting. "We are enjoying the fruits of our investment in recent years in developing computerised defence systems."

A video message purporting to be from the hacking collective, Anonymous, was posted online on Sunday, warning: "We will strike any and all websites that we deem to be in Israeli cyberspace in retaliation for the mistreating of people in Gaza and other areas."

Cyber-attacks launched following the start of the Israeli offensive knocked some sites offline for a short period of time at the end of last week and resulted in others being defaced with pro-Palestinian messages.

Anonymous said on Saturday that it had taken down or erased the databases of nearly 700 Israeli private and public websites, including that of the Bank of Jerusalem finance house.