New York (AFP) - US auto safety officials 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.