US auto safety officials Wednesday expanded an urgent warning over of autos with potentially deadly defective Takata air bags to 7.8 million vehicles, 3.1 million more than previously stated.
Owners of the cars should "take immediate action" to address the airbag issue, the National Highway Traffic Safety Administration said.
The agency said that recalls due to the air bag problem involved 10 different automakers, compared to six mentioned it its Monday warning. The recalls have occurred as far back as 18 months and as recently as Monday.
The vehicles are being recalled because of the risk an air bag could improperly inflate and rupture, potentially sending shrapnel into the car's occupants.
According to reports, the problem has been blamed for several deaths.
The agency said there was "urgency" for motorists in the following areas with warmer climates: Florida, Puerto Rico, areas near the Gulf of Mexico in Texas, Alabama, Mississippi, Georgia, and Louisiana, as well as Guam, Saipan, American Samoa, Virgin Islands and Hawaii.
Investigators suspect that the air bags have a higher risk of rupturing in cars operated in areas with high humidity.
"Responding to these recalls, whether old or new, is essential to personal safety and it will help aid our ongoing investigation into Takata airbags and what appears to be a problem related to extended exposure to consistently high humidity and temperatures," said NHTSA deputy administrator David Friedman.
"However, we're leaving no stone unturned in our aggressive pursuit to track down the full geographic scope of this issue."
Automakers affected by the recalls include: Honda (5.05 million vehicles), BMW (627,615), Chrysler (371,309), Ford (58,669), General Motors (no estimate), Mazda (64,872), Mitsubishi (11,985), Nissan (694,626), Subaru (17,516), Toyota (877,000).
Affected models include such popular sellers as the 2001-2007 Honda Accord, the 2002-2005 Toyota Corolla and the 2005-2007 Ford Mustang.
The 7.8 million cars referred to in the NHTSA warning were only inside the United States.
Worldwide, since the beginning of the year automakers have recalled more than 10 million vehicles with potentially defective Takata air bags.
The recalls have been a black eye for Takata, an 80-year-old Japanese supplier with 43,500 employees worldwide.