WASHINGTON, July 10 (Reuters) - U.S. auto safety

regulators said Wednesday three people have been killed and two

seriously injured by low-cost faulty replacement air bag

inflators.

The National Highway Traffic Safety Administration urged

used car buyers and owners to be aware of the use of substandard

imported inflators that can cause death or serious injury in a

crash. The agency said the inflators, which had been installed

after prior crashes, malfunctioned in subsequent crashes,

sending large metal fragments into drivers.