Five automakers on Thursday widened recalls of cars and trucks with Takata Corp air bags and the U.S. Congress set a hearing next week on the safety issue that has been linked to six deaths, reported Reuters.

Takata last week complied with demands of U.S. safety regulators and doubled the vehicles to be involved in air bag recalls to 34 million, making it the largest recall in American history. The total number globally is more than 53 million vehicles.

The air bags are at risk of exploding with too much force and spewing metal fragments inside the car, regulators say. All six deaths linked to the problem were in Honda Motor Co Ltd vehicles.

The recalls announced on Thursday by Fiat Chrysler Automobiles, Honda, BMW, Ford Motor Co and Mitsubishi Motors Corp are included in the figures issued last week by Takata and U.S. regulator the National Highway Traffic Safety Administration.

Automakers, regulators and Takata have yet to identify the root cause of the problem.

A hearing billed as an update on the Takata safety issue will be held next Tuesday afternoon by the U.S. House Subcommittee on Commerce, Manufacturing and Trade.

U.S. Representative Fred Upton, a Michigan Republican, said on Thursday: “When an air bag – a device built to enhance motorist safety – is actually putting families in peril, we can’t wait years for a fix.”

U.S. lawmakers have complained that both Takata and NHTSA were mishandling the air bag safety issue. NHTSA has tried to show its bite under new head Mark Rosekind, who took the helm in January.

Rosekind will appear before the subcommittee next week. The panel will also hear from Takata Executive Vice President Kevin Kennedy, two leaders of automaker lobbying groups and the director of an independent testing organization.

Fiat Chrysler on Thursday expanded its recalls of vehicles with Takata air bags to about 5.22 million worldwide, involving the 2003 to 2011 model years. About 4.5 million of those vehicles are in the United States. Most of the vehicles have been involved in previous recall campaigns, FCA said.

Ford widened its recall of vehicles with Takata air bags to 1.51 million vehicles globally, including 1.38 million in the United States. The worldwide figure is up from 543,031 before last week’s announcements by NHTSA and Takata, Ford said.

Honda expanded its recall of vehicles with Takata air bag inflators by 350,000 in the United States and 340,000 in Japan.

Since 2008, Honda has recalled about 20 million vehicles worldwide with Takata air bag parts.

BMW said it is widening U.S. recalls of models with Takata air bags to 420,661 vehicles from 140,696.

Mitsubishi Motors Corp widened its recall of vehicles with Takata air bags to 82,784 in the U.S. market.

Nissan Motor Co told NHTSA that it will not expand its recall of U.S. recalls equipped with Takata air bags.