Computer hackers disabled the Tel Aviv Stock Exchange and El Al websites.
The attacks on Monday morning come after hackers over the last two weeks have released online the credit card details of thousands of Israelis and a day after Hamas called on hackers to attack Israeli sites.
The Tel Aviv Stock Exchange's website recovered some operations by mid-Monday morning. Trading was not affected. The bourse's website and trading system are not connected. El Al's website was working by the afternoon.
A group of pro-Palestinian hackers which call themselves “Nightmare” had threatened Sunday to bring down the two websites, according to Ynet.
Also Monday, a Jewish pro-Israel hacker going by the moniker Hannibal published Facebook account information allowing access to the accounts of 20,000 Arab Facebook users. He also claims to have information to allow access to 10 million Iranian and Saudi bank accounts.
"The penetration into Israeli websites opens a new front for electronic resistance and war against the Israeli occupation,” Hamas spokesperson Sami Abu Zuhri said Sunday.