France's ban on the Muslim full face veil has triggered calls on militant online forums for armed retaliation against the country, a US-based terrorism monitoring service said on Wednesday.
Some contributors to the messages seen on the password-protected, invitation-only militant chatrooms this week called on al Qaeda's North Africa arm to "deter" France by staging armed attacks, the SITE service said.
The anonymous threats, presented by the sites as comments by individuals, carry none of the weight of published audio or video statements by Osama bin Laden's al Qaeda or similar established armed groups seeking to attack Western targets.
But Western security officials are concerned that sermons, discussions and videos published on online forums and social networking sites are increasingly used by militants to encourage sympathisers to attempt attacks.
Individuals radicalised online or via email have carried out a handful of attacks in United States and Britain since 2009.
"Sarkozy, leave our sisters alone or we will truly be obligated to act on our words," wrote one participant with the online identity of "Jabeen of Abdullah Azzam", writing on the Arabic-language Shumukh al-Islam forum, SITE reported.
"Declare a war against crusader France!" wrote "al-katebat al-khdra" (the green battalion) on Shumukh al-Islam. "France with such action brought destruction and woes on itself."