The US Customs and Border Protection (CBP) operates the largest drone fleet in the United States. The Defense Department has a much larger fleet, but it is prohibited from operating its drones in the United States for law enforcement missions. The Federal Aviation Administration (FAA) is working on opening US skies for public and commercial drone traffic, but for now CBP is the only agency permitted to operate drones on a daily basis within the nation’s borders.

Most of the missions performed are for the Coast Guard, the Drug Enforcement Administration (DEA), and immigration authorities. Other federal, state, and local law enforcement agencies have been borrowing border patrol drones for surveillance missions, but the drones also serve in disaster relief, drug seizures, and in the search for missing persons.

The Washington Post reports that CBP has a fleet of ten unarmed Predator B drones equipped with infrared cameras and specialised radar. The drones are similar to the Reaper, an Air Force drone also manufactured by General Atomics, a drone producer based in Southern California.

Jenny Burke, a spokeswoman for CBP, says that 95 per cent of the agency’s drone operations “are devoted to CBP’s border security missions.” CBP released the overall totals of drone operations used for other agencies, but the agency did not release the names of those agencies.