A “cybersecurity issue” at MGM Resorts has forced the famous hotel and casino company to shut down many of its systems, according to a statement the company posted just before noon ET on X (formerly Twitter). MGM replaced its homepage with a message apologizing for the site’s outage and providing a list of concierge phone numbers at several locations, like the Aria, The Cosmopolitan, Mandalay Bay, Bellagio, New York-New York, and Vdara.

The issue isn’t limited to MGM’s Las Vegas locations. NBC 10 News in Philadelphia reports that MGM’s Borgata Hotel in Atlantic City was likewise affected by the attack, though hotel representatives didn’t say how. MGM Grand Detroit Casino is also affected, reports Play Michigan, with an X user posting that the casino “has all games running” but that digital keys and MGM’s rewards program are down.

ABC 13 News in Las Vegas confirms the FBI is currently investigating and has been in contact with MGM since Sunday. The outlet reports that hotel guests were unable to access ATMs, buy food, or use their digital room keys.

A post on X this morning showed disabled slot machines at the Aria Resort and Casino in Las Vegas. The X account Las Vegas Locally claimed in a post citing “an insider” that MGM Resorts is the victim of a ransomware attack, though that has not been confirmed. Another X user named Murphy posted a picture they say is from MGM Grand, where slot machines are also apparently out of service.