Hyundai and Kia are recalling more than a half million vehicles in the U.S. because of new problems that can lead to engine fires.

Documents posted Thursday by the government show the Korean automakers are adding three recalls after reports of fires across the country.

The largest recall covers nearly 379,000 Kia Soul SUVs from 2012 through 2016 with 1.6-liter engines.

Abnormal combustion can cause connecting rods to break and pierce the engine block. That can cause oil leaks and fires.

In addition, Hyundai and Kia are recalling 152,000 Tuscon SUVs from 2011 to 2013 and Sportage SUVs from 2011 and 2012 to fix an engine oil pan leak that also can cause fires.

U.S. safety regulators have been investigating Hyundai and Kia engine failures since May of 2016.