FBI: MacDill Package Held 'Possible Energetic Materials'

The FBI said Wednesday that a suspicious package found outside a gate at MacDill Air Force Base in Tampa, Florida, earlier this week contained "possible energetic materials."

An analysis of the material has not been completed, FBI Tampa said in a statement posted on social media Wednesday afternoon. The FBI said the investigation is continuing and provided no further details.

Energetic materials store a large amount of chemical energy and can include explosive materials, fuel, or propellants. The FBI did not respond to an email seeking clarification on what type of material was in the package found Monday outside the MacDill Air Force Base Visitor Center.

Earlier Wednesday, the base went on a shelter-in-place order after a threat was received.

"We take all threats seriously and are taking appropriate measures to prioritize the safety and security of our installation. As a matter of policy, we will not release specifics on what security measures have been implemented," MacDill officials said in a statement posted on social media.

The order was lifted about two hours later, but the base remains on high alert, officials said.

On Tuesday, the base began operating under Force Protection Charlie, referred to as "FPCON CHARLIE." This is the second-highest military security level and allows officials to "implement deliberate security measures proactively."

The advisory said that all personnel at the base "should remain vigilant, follow the direction of security forces, and report any suspicious activity immediately."

The U.S. Central Command, or CENTCOM, which is located at MacDill, is responsible for U.S. military operations in the Middle East, Central Asia, and parts of South Asia.

MacDill is one of the U.S. bases that has been on heightened alert since the war in Iran began.

Last week, all six crew members of a KC-135 refueling aircraft died in a crash while supporting operations against Iran. Three of the crew members were connected to the 6th Air Refueling Wing at MacDill, officials said.