The Islamic State is calling for lone wolf attacks on hurricane relief centers in Houston and Miami.
A confidential document from the Department of Homeland Security's Southeast Bureau details the threats. The document, obtained by CNBC, says ISIS is using social media to rally fighters and sympathizers to wage jihad against the hurricane victims.
"To all the (lone mujahids) in the U,S, (warrior), pop down to Houston and drop in at any of the relief centers housing displaced people from the Houston floods, make sure to bring lots of supplies, gadgets, toys to see if you can help put any (unbeliever) out of their misery," one post cited in the Homeland Security document says.
Others posts say that Allah sent the hurricane and that there were "a lot of opportunities for the soldiers of the Islamic State to target."
But one terror analyst says Americans shouldn't panic over the possible threats.
"These posts appear to be more aspirational than operational, with hopes that their followers would then act on calls for attacks," the analysts notes in the document. "Incidents involving lone wolf attackers have demonstrated the potential danger, lethality, and effectiveness of a rehearsed small arms or knife attack that can be carried out by a single individual with little or no training. It also underscores the potentially higher consequences of an assault attack involving multiple operatives."
The document advises officers to "maintain situational awareness of their surroundings."