A series of tweets were sent from the @CENTCOM account on Monday, starting with one warning: “AMERICAN SOLDIERS, WE ARE COMING, WATCH YOUR BACK. ISIS. “

That tweet and subsequent messages posted in the moments after contain references to a group known as CyberCaliphate and links to documents that are purported to be confidential files pilfered from American military computers, including one cache of files containing slideshows that appear to include details about apparent threats in the Caspian, China, North Korea, Africa and Indonesia.

A statement posted on the website Pastebin shared by the compromised CENTCOM account announced:

“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.

You'll see no mercy infidels. ISIS is already here, we are in your PCs, in each military base. With Allah's permission we are in CENTCOM now.

We won't stop! We know everything about you, your wives and children.

US soldiers! We're watching you!”

Soon after, the hacked Twitter account posted a photo that appears to show United States military personnel surrounded by computers with the caption: “ISIS is already here, we are in your PCs, in each military base."

Last week, the social media accounts for two American television news networks were compromised by persons alleging to belong to Cyber Caliphate — an apparent hacker collective either affiliated or sympathetic to the military group also known as ISIS, or ISIL. It was reported at the time that the US Federal Bureau of Investigation had opened a probe into the matter.