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WASHINGTON (CNN) — Security conditions at U.S. military bases were raised Thursday night because of growing concern of a jihadist threat in the U.S.
The move comes hours after FBI Director James Comey told reporters that there are thousands of ISIS, also known as ISIL, followers online in the U.S.
"We have a general concern, obviously, that ISIL is focusing on the uniformed military and law enforcement," Comey told reporters Thursday.
The order was signed by Admiral William Gortney, head of the U.S. Northern Command, which oversees all U.S. military installations in the continental U.S.
(CNN) The Department of Defense raised the level of security conditions at U.S. military bases Thursday night to "Bravo," because of the growing concern of a terrorist threats in the United States.
But what does the "Bravo" level specifically mean?
The Force Protection Condition, or FPCON, is a threat level system that is overseen and decided by the Department of Defense. It has various levels that show security concern in the country. According to the list, the Antiterrorism Program "provides guidance and establishes standards for implementing the levels" in the Department of Defense. Local commanders decide which level is appropriate.
The change could mean more checks of vehicles entering military bases and identity checks of all personnel.
The level change comes after FBI Director James Comey made comments about Elton Simpson, one of the two Texas attackers of the Prophet Muhammad exhibit in Garland, Texas who was killed Sunday by a guard when they opened fire.
"I know there are other Elton Simpsons out there," Comey said, adding that the FBI has hundreds of investigations in the U.S. of possible extremists influenced by known ISIS recruiters.
"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.
Davis declined to specify the new security measures. But a U.S. official confirmed to CNN that U.S. military bases are now at "Force Protection Bravo," which is defined by the Pentagon as an "increased and predictable threat of terrorism." U.S. bases generally have not been at this level since the 10th anniversary of the Sept. 11 attacks, the official said.
A U.S. military official said the order to raise the force protection level to "Bravo" also applies to all National Guard installations, recruiting stations, and ROTC detachments, though practically speaking, the official acknowledges it will be difficult for the ROTC detachments to do much more than security awareness.
"We are doing this as a prudent measure due to a lot of things in the news lately," Davis said. "While this change is not tied to a specific credible threat, recent events have led us to recognize the need to take prudent steps to ensure that our security measures can be increased quickly."
The change could mean more checks of vehicles entering bases, and 100% identity checks of all personnel. Davis emphasized "this is the new normal that we are going to have increased vigilance and force protection. We seek to be unpredictable."
CNN's Evan Perez contributed to this report.
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