Social media accounts run by Central Command, the US military command covering the Middle East, have been hacked by a group claiming to be linked to the Islamic State of Iraq and the Levant, known as Isis.

The hackers posted a number of messages on Centcom’s Twitter feed, including screenshots of what they claimed were internal Pentagon documents. The Florida-based military command, which coordinates operations against Isis in Iraq and Syria, also had its YouTube account hacked.

Centcom’s Twitter feed was suspended just after 1800 GMT, or 1300 eastern time, about 20 minutes after the hack first started, and the suspension of the YouTube account followed minutes later. A Pentagon official told NBC News that the attack was “embarrassing” but did not represent a security threat.