As the Israeli army rains shells on the Gaza strip Thursday, it’s also taken the offensive online, posting videos of its attacks on Hamas targets and live-tweeting its campaign. Now the hacktivist group Anonymous has responded with a digital bombardment of its own.

In a coordinated action that began at 3 a.m. ET Thursday, hackers attacked web sites belonging to the Israel Defense Forces, the prime minister’s office, Israeli banks, airlines and security companies by flooding them with web traffic, in an operation they called #OpIsrael. “We Anonymous will not sit back and watch a cowardly Zionist State demolish innocent people’s lives.” reads one message posted to a defaced site, along with an image of smoke rising over what appears to be a Palestinian city.

Anonymous Twitter accounts provided links to what they described as an Anonymous Gaza Care Package with tools for staying online if Israel cuts Internet service the Gaza Strip during its military action. Another hacker group, Telecomix, provided its own detailed instructions in English and Arabic for using dial-up connections.

"Anonymous does not support violence by the I.D.F. or by Palestinian Resistance/Hamas. Our concern is for the children of Israel and Palestinian Territories and the rights of the people in Gaza to maintain open lines of communication with the outside world," reads a press statement from Anonymous.