DETROIT (AP) — U.S. auto safety regulators are investigating complaints that the engines in three Chrysler models can stall without warning.

The probe covers more than 192,000 Chrysler 300C luxury cars, Dodge Charger muscle cars and Dodge Magnum wagons from the 2006 model year. The cars have 5.7-liter or 6.1-liter V-8 engines.

The agency says it has 54 complaints from owners that engines stalled while the cars were being driven. In all cases the stalling happened after the cars were refueled. Forty-eight of the owners said they had several stalling incidents, and seven said they had trouble restarting the cars.

The agency says the number of complaints has increased, with half coming in the last eight months.

Investigators will check how often the problem happens and determine if a recall is needed.