WASHINGTON -- The National Highway Traffic Safety Administration, worried that too many 2006 model-year Ford Rangers and Mazda B-series pickups with defective Takata airbags remain on the road, with owners to schedule a free repair at an authorized dealership.

In January, Ford Motor Co. urged 2,900 Ranger owners to stop driving immediately until they can get replacement parts after a second death was linked to airbag inflators from the same production lot. A month later Ford expanded the "Do Not Drive" warning to 33,000 vehicle owners. Mazda issued similar warnings.

According to the manufacturers, 44 percent of the 33,320 impacted 2006 Ford Rangers have been mitigated, and 55 percent of the 2,205 impacted Mazda B-series trucks have been mitigated.

Both companies are offering to tow vehicles to a dealership for repair, and provide loaner vehicles free of charge.

"I cannot stress strongly enough the urgency of this recall -- these airbags are dangerous," said NHTSA Deputy Administrator Heidi King in a statement. "Every vehicle must be accounted for now."

Owners can go to NHTSA's website and search by VIN whether their vehicle is included in any recall.

The propellant in Takata airbags can degrade over time or be affected by humidity, leading to an explosion that can project shrapnel into the passenger compartment if deployed. Takata airbags are responsible for 22 deaths worldwide, most of them in the U.S.

Ford recalled 2004-2006 Rangers in 2016 for their defective airbags, but they were not identified as high-risk or accompanied with a "Do Not Drive" instruction.

You can reach Eric Kulisch at ekulisch@crain.com