The Air Bridge Denial (ABD) Program is an anti-narcotics program operated by the U.S. Central Intelligence Agency in Colombia and Peru. Starting in the 1990s, it targets traffickers transporting illicit drugs through the air by forcing down suspicious aircraft, using lethal force if necessary. The program was suspended in April 2001 when a legitimate civilian aircraft was shot down in Peru and two U.S. citizens were killed. It was restarted in Colombia in August 2003 after additional safeguards were established.