The Pentagon has confirmed that the Youtube and Twitter accounts of the U.S. military's Central Command have been suspended after a cyberattack by hackers who claim to be aligned with the militant group Islamic State (IS).
A Pentagon spokesman said the attack is "embarrassing but not a security threat."
Later, U.S. Central Command (Centcom) said its operational networks were not compromised by the hackers and there was "no operational impact."
Centcom is based at an air base in Florida and handles U.S. military operations covering the Middle East and Central Asia.
The group, called CyberCaliphate, posted a message on the Centcom Twitter feed on January 12 saying: "In the name of Allah, the Most Gracious, the Most Merciful, the CyberCaliphate continues its CyberJihad."
It also posted the names and addresses of U.S. military generals online, as well as purported U.S. military plans for scenarios involving China and North Korea.
CyberCaliphate has been under investigation by the FBI since it launched hacks against the Twitter pages of several U.S. news organizations in early January.
The group also claims it hacked into the data bases of the FBI and says it is planning cyberattacks against homes and offices across the United States.