WASHINGTON: Despite the ease with which an alleged terrorist got an explosive aboard a Detroit-bound flight, the Obama administration says the incident shows the US aviation security system worked.

Billions of dollars have been spent on aviation security since the Sept. 11, 2001, terrorist attacks, when commercial airliners were hijacked and used as weapons.

Much of that money has gone toward training and equipment that some security experts say could have detected the explosive device the 23-year-old Nigerian man is believed to have hidden on his body on a flight from Amsterdam to Detroit.