The Tel Aviv Stock Exchange's (Tase's) Web site has been offline this morning, apparently down for "maintenance" hours after a Saudi hacker warned it would be the next target in an escalating cyber-war.
The Jerusalem Post says that it received a warning from hacker OxOmar on Sunday that another collective planned to take down the Web sites of Tase and ElAl Airlines on Monday at 10.00am local time.
Both sites duly fell over although they currently display messages insisting that they are down "due to maintenance". The Tase trading system is unaffected.
The alleged attacks are the latest salvos in a series of cyber-attacks over the last few weeks that began when OxOmar, a member of Saudi hacking collective Group-XP, posted the personal information, including some credit card details, of around 400,000 Israelis.
Last week an Israeli hacker retaliated by publishing details of around 200 Saudi credit cards and threatening to post more.
The attacks have elicited a strong political response, with Israel's deputy foreign minister comparing the initial incident to terrorism and threatening retaliation against the perpetrators.
At the weekend, Sami Abu Zuhri, a spokesman for Hamas, the group that controls Gaza and is considered a terrorist organisation by Israel and the US, stoked the fires further by claiming: "Penetrating Israeli websites means opening a new field of resistance and the beginning of an electronic war against Israeli occupation."