Homeland Security Investigations officials described the Hyundai raid as the agency’s largest single-site enforcement operation to date

Federal agents raided a Hyundai facility in Georgia yesterday, detaining 475 individuals—most of them South Korean nationals.

Homeland Security Investigations officials described it as the agency’s largest single-site enforcement operation to date.

The facility was co-owned by Hyundai and LG Energy Solution.

South Korea has expressed concerns, and the arrests are expected to heighten tensions between Seoul and Washington.

In July, the South East Asian nation committed to $350 billion in US investments in an effort to reduce President Donald Trump’s proposed tariffs on South Korean goods, which were later set at 15%.