Al-Qaeda’s main Internet forums have been dark for 11 days in what experts believe is the work of cyber-attacks sponsored by the US intelligence community.

The Al-Qaeda Shumukh al-Islam forum went offline on March 22. Since then four other Al-Qaeda affiliated forums have also gone down.

“The media arena is witnessing a vicious attack by the cross and its helpers on the jihadi media castles,” the administrator for the site reportedly posted online.

Al-Qaeda has long leveraged the Internet as a recruiting platform, and as a means of coordinating attacks between Jihadists worldwide.

Will McCants, a former State Department counterterrorism official, told the Washington Post the Al-Qaeda outage “sure looks like a takedown.”

He said if the online sites go down due to technical problems “usually they will get on another site and say we’ve got administrative problems.”

Evan Kohlmann, senior partner at Flashpoint Global Partners, told the Post the recent attacks on al-Qaeda web sites have begun to affect contacts between Jihadists worldwide.

“At least temporarily, the social networking among jihadists has been disrupted,” he said. “The remaining forums are really struggling to attract the participation of users.”

US intelligence officials have relied on electronic eavesdropping on al-Qaeda forums to gather insights into conversations among Islamic terrorists with some officials arguing against attempts to shut down the forums, saying they provide valuable intelligence.

A. Aaron Weisburd, a senior fellow at the Homeland Security Policy Institute who runs Internet Haganah, a site that tracks extremist forums, told AFP the disruptions would have far reaching implications.

“It leaves the rank-and-file to guess which messages and which messengers are genuine al-Qaeda, and provides undercover operators with new opportunities to disrupt the movement,” he said.