Immigration officials arrested nearly 500 workers, most of them South Korean citizens, at the construction site of an electric vehicle battery plant in Georgia on Thursday, as the Trump administration continues its far-ranging crackdown on illegal immigration.

The raid, which U.S. officials have called the largest-ever Homeland Security enforcement operation at a single location, stirred tensions with the South Korean government, a valued trade partner of the United States….

The plant has been the subject of investigative reports by the local TV station WTOC about poor safety conditions and the use of unauthorized laborers. At least three workers have died at the complex, according to local law enforcement.

Officials from both Hyundai and LG Energy Solution said the safety of their workers was critical and announced their own inquiries into the raid…

In a statement, LG Energy Solution said the company prioritizes “the safety and well-being of our team” and that its $25 billion investment in North American manufacturing would create about 14,000 jobs in the United States by 2027. Hyundai said the company was “committed to maintaining the highest safety standards.” It also said its employees “are required to comply fully with U.S. laws and regulations.”