IHG Hotels & Resorts' booking channels and apps are experiencing widespread disruptions after the company's technology systems were impacted by what IHG called "unauthorized activity."
According to IHG, the disruptions began Monday.
On the IHG Hotels & Resorts website, a message states that users "may have challenges booking a new reservation, accessing information about your upcoming reservations and accessing your IHG One Rewards account," and should contact a property directly in order to make, amend or cancel a booking.
In a statement, IHG said that the company had implemented response plans in the wake of the breach and that regulatory authorities had been notified. IHG has tapped external specialists to investigate the incident.
IHG and its technology suppliers are working to restore service, said IHG.
IHG has 17 brands, including InterContinental, Holiday Inn, Holiday Inn Express, Kimpton, Crowne Plaza and Hotel Indigo.