Terror threat level increased at U.S. military bases
(CNN) -- Security conditions at U.S. military bases were raised Thursday night, because of growing concern of a jihadist threat in the U.S
It comes hours after FBI Director James Comey raised the prospect there are thousands of ISIS followers online in the U.S.
"We have the same concern about the potential threat posed by violent homegrown extremists," said Captain Jeff Davis, spokesman for the U.S. Northern Command which oversees all U.S. military installations in the continental U.S.
The order was signed by Admiral William Gortney, head of the command.