(Twitter)

Newsweek's official Twitter account was hijacked Tuesday morning by a group calling itself "Cyber Caliphate," which claims to be affiliated with the Islamic State. The group changed the page's main image and shared menacing messages, including one about President Obama and his family.


(Twitter)

The account was also used to share what appeared to be documents relating to a military cybersecurity defense program, although their authenticity is unclear.

Newsweek regained control of the account within half an hour. "We can confirm that Newsweek's Twitter account was hacked this morning, and have since regained control of the account," Newsweek said in a statement. "We apologize to our readers for anything offensive that might have been sent from our account during that period, and are working to strengthen our newsroom security measures going forward."

Federal Bureau of Investigations did not immediately return a call for comment. A Secret Service spokesman said the agency was "aware of the incident and taking appropriate action."

The Cyber Caliphate name and similar imagery have been used in a number of  Twitter hijacking and Web site hacks in recent months — including some attacks that targeted local news outlets.

Last month, the U.S. Central Command's Twitter and YouTube accounts fell prey to a similar attack. Malaysia Airlines' Web site was attacked in January.

Other outlets have suffered Twitter hijacking attacks before — including the Associated Press, which in 2013 was used to tweet out a false message claiming there was an attack at the White House and the president was injured.