Fort Pierce police and the FBI are investigating whether four bomb threats made across the Treasure Coast over eight days are connected, including a Saturday threat against HCA Florida Lawnwood Hospital. The hospital threat, reported Saturday afternoon by email, followed similar patterns to threats made at Indian River State College on Friday and at two Treasure Coast high schools, according to Fort Pierce police. Three of the four threats were sent by email.

Police officers searched the Lawnwood Hospital building Saturday afternoon and evacuated visitor areas as a precaution. Police cruisers surrounded the hospital, and officers gave the all-clear several hours later. Patient care was not interrupted. No explosives were found.

The series of threats began September 4 with a called-in threat at Fort Pierce Central High School, where students were evacuated while deputies investigated. Investigators say the email address used to send the threat to Martin County High School had been hacked and may have been connected to a suspect in Russia. Police say none of the four threats were found to be credible, but officers continue to take each one seriously.

Major Michael Santiago with the Fort Pierce Police Department said officers have to treat every threat seriously. Santiago said once investigators narrow down those making threats, they will find and prosecute them. All four incidents remain under investigation, and police are asking anyone with information about the threats to contact investigators.