US agency probing 4 Ford models over engine stalls

US safety regulators are investigating Ford sedans and sport utility vehicles following complaints of a sudden reduction of engine power.

The investigation involves nearly 725,000 cars, covering the 2009-11 models of the Ford Escape and Fusion, and the Mercury Mariner and Milan, according to a notice posted on the National Highway Traffic Safety Administration's website.

"Consumers have reported incidents of electronic throttle body failure while driving, resulting in sudden reduction of engine power," said the notice by the NHTSA.

The investigation is in response to nearly 1,500 complaints; the problems have resulted in three crashes or fires and one injury incident, the notice said.

The probe began after the North Carolina Consumers Council contacted the NHTSA with reports of two complaints.

A Ford spokesman said the company will cooperate with the agency.