The FBI has charged a brother and sister in connection with an alleged improvised explosive device (IED) found near the visitors center at MacDill Air Force Base.

The device was placed on March 10 but discovered by base personnel on March 16, and forensic analysis is ongoing.

Alen Zheng faces charges including attempted damage of government property, unlawful making of a destructive device, and possession of an unregistered device, while Ann Mary Zheng is charged with accessory after the fact and evidence tampering.

Authorities traced the suspects through surveillance footage, cell phone records, and other evidence, and both allegedly attempted to flee to China after placing the device, ABC News has reported.

FBI officials emphasized that the device was potentially deadly, though the motive for the attack remains unknown.