Pro-Islamic State (Isis) hackers have commandeered the official Twitter account of the US Central Command.
@CENTCOM feed was briefly plastered with a series of messages praising the Islamist group and threatening US soldiers before it was suspended.
The account's profile photo was changed to one including the words "I love you isis." and "Cybercaliphate".
"American soldiers, we are coming, watch your back. Isis," a message read. "In the name of Allah, the Most Gracious, the Most Merciful, the CyberCaliphate continues its CyberJihad."
The hackers claimed to have hacked into the computers of US military bases and posted photos of what they said were spreadsheets listing contact information for retired army officers.
"ISIS is already here, we are in your PCs, in each military base. With Allah's permission we are in CENTCOM now," a message read.
"While the US and its satellites kill our brothers in Syria, Iraq and Afghanistan we broke into your networks and personal devices and know everything about you."
What appeared to be military maps with information on China and North Korea were also posted on the account.
A senior defense official said US Central Command was taking appropriate measures to address the matter.