The government has opened an investigation into some Ford Escape and Mazda Tribute sport utility vehicles after receiving complaints of engine compartment fires, Ford Motor Co. (F) said Friday.

The investigation involves more than 600,000 SUVs from the 2001-2003 model years. The National Highway Traffic Safety Administration said it had received eight complaints of engine fires around the antilock braking system's electronic control module.

Ford spokeswoman Kristen Kinley said Friday there have been no reports of injuries linked to the fires and the automaker was cooperating with the agency's investigation.

"At this time it's too early in the investigation to speculate on the outcome," she said.

Ford and NHTSA said the review was not connected to a two-year investigation of engine fires linked to the cruise control systems in Ford trucks, SUVs and vans. That investigation led to the recall of about 5.8 million Ford vehicles in 2005 and 2006.

In the Escape investigation, NHTSA said five of the eight complaints described the fires as occurring after the SUV had been parked. In two additional cases, NHTSA received reports of smoke or melted electrical connectors and wiring near the antilock braking system in Escapes.

NHTSA said the control module is an on-board diagnostic and control computer that monitors the system during normal driving conditions and when the antilock brakes are being used. The module is located in a circuit that is always powered regardless of whether the ignition is on or off.

The Escape and Tribute SUVs share similar underpinnings. The investigation does not involve the Ford Escape Hybrid, which was first introduced in 2004.

The government's preliminary evaluation will review the frequency, scope and safety consequences of the alleged defect. Defect investigations can sometimes lead to vehicle recalls.