WASHINGTON (AP) — A senior defense official is confirming that U.S. Central Command's Twitter and YouTube sites have been compromised.

The sites were taken over today by hackers claiming to be working on behalf of the Islamic State militants. American and coalition fighters have been targeting the group with airstrikes in Iraq and Syria.

The Twitter site was filled with threats that said "American soldiers, we are coming, watch your back." Other postings appeared to list names and phone numbers of military personnel as well as PowerPoint slides and maps. The hackers titled the Twitter page "CyberCaliphate" with an underline that said "i love you isis."

IS militant videos were posted on the YouTube site, purporting to show military operations and explosions.

The military has suspended the Twitter site and the defense official says Central Command is taking appropriate measures to address the hacking.

The official spoke on condition of anonymity because the official was not authorized to speak about it publicly on the record.