U.S. immigration authorities raided Hyundai’s massive EV manufacturing site in Bryan County, Georgia, halting construction at an adjacent battery plant and detaining about 450 people in an immigration enforcement operation.

Homeland Security said the raid was part of a criminal probe into unlawful employment practices, while South Korea’s government expressed concern over the treatment of its citizens and businesses.

The $7.6 billion project, billed as Georgia’s largest economic development investment, remains central to Hyundai’s U.S. EV expansion, though the battery plant construction has been paused, CBS News has reported.

Hyundai said vehicle production at the site was not disrupted.