US Centcom's Social Media Accounts Apparently Hacked by IS Backers

Hackers claiming to be affiliated to Islamic State (IS) jihadist group on Monday hacked the Twitter and YouTube accounts of US Central Command.

The hackers also leaked online what they claimed were internal documents, according to international media reports.

"American soldiers, we are coming, watch your back! ISIS. #CyberCaliphate," said the first tweet posted on the account after it was apparently hacked.

Another tweet read "ISIS is already here, we are in your PCs, in each military base," using the acronym ISIS for Islamic State in Iraq and Syria, another name for the militant group.

Two Islamic State propaganda videos were posted on the Central Command's YouTube account, entitled "O Soldiers of Truth Go Forth", and "Flames of War".

It wasn't immediately clear who was behind the cyber attack, which took place as US President Barack Obama was preparing to deliver a speech on cybersecurity. 

Central Command (Centcom), one of nine unified commands in the United States military, said it was taking "appropriate measures to address the matter". The Twitter and YouTube accounts were suspended shortly after the first tweets and uploads.

Some of the documents posted online appeared to list names and phone numbers of members of the US military as well as PowerPoint slides and maps, the BBC said in its coverage of the news.

According to US Government officials, which spoke to NBC News, the Twitter and YouTube accounts weren't classified, and that none of the information posted by the hackers was actually classified. The names and contact information are "official use only," the officials said.