In its weeklybulletin, the OCHA said it had "received reports of looting of houses of displaced people, markets and businesses" in the camp and Kutum town.
The official said the warning was sent in a weeklybulletin to 18, 000 state and local agencies, a lightly classified alert that outlines possible tactics terrorists could use.
In the FBI's weekly intelligence bulletin, dated Wednesday and sent out to state and local law enforcement offices, the agency said the U.S. government has no "credible threats about specific attacks, " according to a senior administration official who has a copy of it.