"American soldiers, we are coming, watch your back, ISIS," the hackers posted on the U.S. Central Command Twitter feed, using an acronym for the hardline Islamist group, which has taken control of parts of Syria and Iraq.

Of course, it only managed to take over the Army’s Twitter and YouTube feeds which is annoying rather than important

US officials acknowledged that the incident in which the accounts were "compromised" for about 30 minutes was embarrassing but played down the impact. The FBI said it was investigating.

Pentagon spokesman Army Colonel Steve Warren said the Defense Department "views this as little more than a prank, or as vandalism."