All gates at MacDill Air Force Base are closed to inbound and outbound traffic.

TAMPA, Fla. — A threat against MacDill Air Force Base has prompted a shelter-in-place order Wednesday morning.

All gates at the base are closed to inbound and outbound traffic. 

“We take all threats seriously and are taking appropriate measures to prioritize the safety and security of our installation,” MacDill officials told 10 Tampa Bay News.

Military families at the base told 10 Tampa Bay News they began receiving the shelter-in-place messages around 11 a.m. They also shared that the base clinic was evacuated out of an abundance of caution.

Emergency crews are responding to the scene.

“As a matter of policy, we will not release specifics on what security measures have been implemented,” MacDill officials added.

The threat comes less than 24 hours after MacDill raised its terror threat level to FPCON Charlie following a suspicious package investigation at the base Monday. The increased threat level allows military officials “to implement deliberate security measures proactively.”

FPCON Charlie is the second-highest force protection level for military installations. 

“It is implemented when an incident occurs or intelligence is received indicating some form of terrorist action targeting personnel or facilities is likely,” according to the Defense Logistics Agency

Monday’s suspicious package investigation shut down the base’s Dale Mabry gate and Visitor Center for hours as FBI special agent bomb techs and Tampa police responded. The package was cleared from the scene Monday evening, although the investigation into its contents is ongoing.

This is a breaking news story. Check back for updates.