A US military Twitter feed has been hacked by people claiming sympathy to the Islamic State militant group, Reuters reports.
The US Central Command Twitter account and its YouTube account were suspended after being compromised.
After the hacking, the heading of the Central Command Twitter account showed a figure in a black-and-white headscarf and the words “CyberCaliphate” and “I love you ISIS”, using an acronym for the Islamic State group.
The Twitter feed had several messages from hackers, including one telling American soldiers to "watch your back," and the YouTube account had two videos that appeared to be linked to Islamic State.
US defence officials told Reuters the hacking was an embarrassment but did not appear to be a security threat.
The apparent infiltration came as President Barack Obama prepared to outline new proposals to protect the country's Internet systems from cybersecurity threats.
Central Command handles American military operations covering the Middle East and Central Asia. It oversaw the wars in Iraq and Afghanistan and is managing the US air strikes against Islamic State positions in Iraq and Syria.