The Northeast Intelligence Network, a group of private counter-terrorism experts, has issued a warning about potential terrorist attacks on Jewish sites and civilians in the United States. The group reported that there has been a “dramatic spike” in communication on web sites used by radical Islamic terrorists and followers.

“There is a call to action being made over the Internet by posters who have established a perceived level of legitimacy. These posters are the individuals who have achieved a following in the virtual world, based in part on their history of accuracy relative to terrorist operations and their posting history,” Douglas J. Hagmann, the group’s director, said on the Northeast Intelligence Network website.

“Their message is to take action against Jews anywhere in the world, including inside the U.S., Canada and all Western countries, as well as their American backers.”

Hagmann added that some of the web postings suggested the targeting of synagogues and schools, specifically mentioning attacks on Jewish children.

The Israeli military offensive into Gaza has caused large demonstrations against the action to take place in the West, sometimes resulting in clashes between the protestors and security forces, as has happened in Paris. Roughly 12,000 people protested the offensive into Gaza in London on January 10, and over 90,000 protested throughout France, according to Agence-France Presse. The report said that some protestors had held up signs of the leaders of Hezbollah and Hamas, and expressed solidarity with the terrorist organizations.

The conflict has caused some outbursts of hatred and violence. In Toulouse, France, a car was set ablaze and then slammed into a synagogue, according to BBC News. Ha’aretz has reported that a radical Islamic web site had postings from individuals creating a list of Jewish citizens in the United Kingdom to target for assassination.