The sources, who spoke on condition of anonymity, said the warning issued by the FBI last week was general and singled out no specific target, but referred specifically to natural gas infrastructure such as pipelines.
One source characterized the warning as similar to one issued earlier this month on potential attacks against West Coast bridges that prompted security alerts, but no evidence of actual terrorist intentions, AP said.
"We have received uncorroborated information that Osama Bin Laden may have approved plans to attack natural gas supplies in the United States," said the FBI memo, adding that the information was "from a source of undetermined reliability."
The FBI warning continued that "such an attack would allegedly take place in the event that either Bin Laden or Taliban leader Mullah Omar are either captured or killed."
