Jan. 27 (UPI) -- Several social media accounts belonging to NFL teams, including the Super Bowl-bound Kansas City Chiefs and San Francisco 49ers, appeared to have been infiltrated by a hacker group over the past two days.
The NFL's own Twitter and Facebook accounts also were apparently hacked, as fans from around the world prepare for Super Bowl LIV on Sunday in Miami.
On Sunday, the Chicago Bears' official Twitter account was the first to start showing messages from a hacker group that called itself "OurMine." One of the messages on the account said the cyber attack was to announce that "we're back" and to "show people that everything is hackable."
In the since-deleted tweets, the group claiming responsibility said it could "improve your accounts security" and provided an email for additional information.
Similar messages popped up on other team feeds as well as the NFL's Facebook account Monday. Among the social media pages impacted by the hacker group were the Houston Texans, Buffalo Bills, Minnesota Vikings, Green Bay Packers, Dallas Cowboys, 49ers and Chiefs.
The tweet on the Packers' account was published multiple times after being deleted. Several other teams had their Twitter profile pictures and header images removed.
"OurMine" has previously been linked to other social media hacks, claiming credit for breaking into Facebook CEO Mark Zuckerberg's Twitter and Pinterest accounts. The group also took credit for accessing the Twitter accounts of Netflix and Marvel, among other organizations.