Islamic State sympathisers have hacked the U.S. Central Command’s Twitter and Youtube accounts, posting internal military documents online and declaring “we are coming, watch your back”.

The United State’s military command, which is in charge of air strikes against the Islamic State in Iraq and Syria, was forced to suspend its Twitter account after it was hacked by a group called ‘CyberCaliphate’.

• Why we should call Islamic State ‘Daesh’
• Paris shooting: free speech in the firing line

The hackers posted a series of foreboding Twitter messages with the warning “we won’t stop”.

“American soldiers, we are coming, watch your back,” one tweet started.

Other tweets warned “we know everything about you, your wives and children… we’re watching you”.

The page was hacked with slogans like “i love you ISIS”.

Internal military documents were also posted online, but did not contain sensitive material.

One of the documents marked “For Official Use Only” depicted scenarios of possible conflict with China and North Korea.

The group also posted propaganda videos on the U.S. Central Command’s Youtube channel.

White House spokesman Josh Earnest said the hack was “something we take seriously” but added there was a “pretty significant difference between what is a large data breach and the hacking of a Twitter account”.

Twitter/@Reuters