The package was discovered around 11:20 a.m. Monday, prompting emergency responders to shut down the base’s Visitor Center and Dale Mabry gate.

TAMPA, Fla. — The FBI shared new details Wednesday just two days after a suspicious package was found at MacDill Air Force Base’s Visitor Center. 

The package was discovered around 11:20 a.m. Monday, prompting emergency responders to shut down the base’s Visitor Center and Dale Mabry gate “out of an abundance of caution.” Traffic was also diverted for hours to the Bayshore gate as special agent bomb techs from the FBI Tampa office and Tampa police were on scene. 

On Wednesday, the FBI said field screening was conducted on the contents of the package, with possible energetic materials identified. However, final lab analysis is not yet complete. 

The investigation into the package comes as the base was under a brief shelter-in-place following a threat on Wednesday morning. The threat came less than 24 hours after MacDill raised its terror threat level to FPCON Charlie on Tuesday, which is the second-highest force protection level for military installations. 

According to the Defense Logistics Agency, it’s implemented when “an incident occurs or intelligence is received indicating some form of terrorist action targeting personnel or facilities is likely.” The increased security level can allow for additional security measures at gates or additional security forces.

As the base adds security protection, tensions in the Middle East continue, and MacDill continues to mourn the loss of three U.S. airmen killed on March 12 when a refueling aircraft crashed during a combat mission in western Iraq.

On Saturday evening, the 6th Air Refueling Wing identified the crew as Major Alex Klinner, Captain Ariana Savino, and Technical Sergeant Ashley Pruitt. 

The airmen were stationed at Sumpter Smith Joint National Guard Base in Birmingham, Alabama, and assigned to MacDill’s 6th Air Refueling Wing.

The three had been deployed for less than a week, a source tells 10 Tampa Bay News.