Ardent Health Services, which oversees 30 hospitals across the U.S., said it had shut down a significant number of its computerized services.

Hospitals in at least three states are diverting patients from their emergency rooms after a major cyberattack hit their parent company last week.

Ardent Health Services, which oversees 30 hospitals across the U.S., said Monday that it had been the victim of a severe ransomware attack in Oklahoma, News Mexico and Texas, forcing it to take action.