Alberta Health Services said nearly two dozen surgeries at the Walter C. MacKenzie Health Sciences Centre were postponed Monday, after an email prompted a police investigation.

In a statement, an AHS spokesperson told CTV News that 23 surgeries were postponed at the facility, which includes the University of Alberta Hospital, the Mazankowski Alberta Heart Institute and the Stollery Children’s Hospital.

The statement said the decision to postpone the surgeries came as a precaution, after an email received by AHS led to an investigation that members from the Edmonton Police Service assisted with.

On Monday evening, AHS said emergency surgeries would only be performed at those three sites.

As the investigation continues, AHS said further details would not be released.

UPDATE (Tuesday, May 5, 2015): AHS said officials had decided to go ahead with scheduled procedures on Tuesday.