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.