Siblings Face Charges After Explosive Device Found Near US Military Base in Florida

One of the siblings remains in China after allegedly fleeing there with his sister, who was arrested upon returning to the United States.

Tampa police block traffic along South Dale Mabry Highway near the main entrance of MacDill Air Force Base after a suspicious package was reported at the gate in Tampa, Fla., on March 16, 2026. Octavio Jones/AFP via Getty Images

A brother and sister face federal charges after an explosive device was found outside a U.S. military base in Florida, which investigators say they planted before fleeing to China.

U.S. Attorney Gregory W. Kehoe announced the indictments Thursday in a joint news conference with the FBI.

Alen Zheng, 20, and Ann Mary Zheng, 27, both U.S. citizens and residents of Land O' Lakes, Florida, were charged in separate indictments filed on Wednesday. Alen Zheng is still in China after allegedly fleeing there with his sister in the wake of the incident. Authorities arrested Ann Mary Zheng upon her return to the United States. Their mother has been detained pending deportation for a visa overstay.

Kehoe said the device found at MacDill Air Force Base in Tampa could have been “very deadly.” Alen Zheng faces up to 40 years in prison if found guilty of attempting to damage government property and unlawfully making and possessing the device. Ann Mary Zheng faces up to 30 years if convicted of witness tampering and acting as an accessory after the incident.

“We’re exploring every avenue we can to get him back to the United States,” Kehoe said. The siblings have not been linked through evidence to working on behalf of any foreign government.

The device was placed on March 10 in front of the base’s visitor center gate. Minutes later, Alen Zheng made a 911 call reporting a bomb, according to authorities. Despite initial searches, the device was not found until March 16.

Investigators swiftly tied the 911 call to Alen Zheng via phone data and surveillance video in which the siblings’ Mercedes-Benz SUV appeared near the gate. The pair had sold the vehicle, purchased plane tickets, and traveled to China by March 12.

Agents later found explosive elements at the family residence, as well as residue matching the device in the cleaned SUV. Authorities flew the device to an FBI laboratory in Huntsville, Alabama, for analysis.

An FBI statement noted that the suspicious package held “possible energetic materials” and led to a shelter-in-place order at the base.

“We take all threats seriously and are taking appropriate measures to prioritize the safety and security of our installation,” MacDill AFB said in a post on Facebook after the device had been found. “As a matter of policy, we will not release specifics on what security measures have been implemented.”

MacDill Air Force Base serves as headquarters for U.S. Central Command, overseeing military operations across the Middle East, Central Asia, and parts of South Asia. The base has operated under increased alert since the war in Iran commenced.

A St. Petersburg man, Jonathan James Elder, was placed under arrest this week for allegedly making threatening phone calls to the base days after the device’s discovery. Investigators have not linked him to the Zheng case or any device.

“Did you enjoy your pipe bombs at the front gate of MacDill?” Elder allegedly said in the phone call.