Officers detained 475 people during an immigration raid on a Hyundai factory for electric vehicles in Georgia.
The majority of those detained at the 3,000-acre site west of Savannah are from South Korea, according to Steven Schrank, special agent in charge at Homeland Security Investigations.
Mr Schrank said the raid was the “largest single-site enforcement operation” in the history of the agency and followed an investigation of several months, which involved leads from community members and former workers.
The spokesman for the South Korean foreign ministry, Lee Jaewoong, said there was a “large” number of South Koreans among those detained in the raid, but did not provide an exact number.
He said the detained workers were part of a “network of subcontractors” and that the employees worked for several different companies on the Georgia site.
Mr Lee said South Korea’s foreign ministry is dispatching diplomats from its embassy in Washington and consulate in Atlanta to the site, and plans to form an on-site response team centred on the local mission.
“The business activities of our investors and the rights of our nationals must not be unjustly infringed in the process of US law enforcement,” Mr Lee added.
The Department of Homeland Security said in a statement that agents executed a search warrant “as part of an ongoing criminal investigation into allegations of unlawful employment practices and other serious federal crimes”.
The manufacturing site, which employs about 1,200 people, has been hailed as the largest economic development project in the state’s history by Governor Brian Kemp and other officials.
Hyundai Motor Group, the biggest automaker in South Korea, started manufacturing electric vehicles at the $7.6bn (£7.4bn) site a year ago and partnered with LG Energy Solution to build an adjacent battery plant, which is set to open in 2026.
ICE spokesman Lindsay Williams confirmed the raid and said agents were focused on the construction site for the battery plant.
LG said in a statement that it was “closely monitoring the situation and gathered all relevant details”. The firm said it couldn’t immediately confirm how many of its employees or Hyundai workers had been detained.
“Our top priority is always ensuring the safety and well-being of our employees and partners. We will fully cooperate with the relevant authorities,” LG said.
Hyundai and LG’s battery joint venture, HL-GA Battery Company, said in a statement that it’s “cooperating fully with the appropriate authorities” and paused construction of the battery site to assist the investigation.
Operations at Hyundai’s electric vehicle manufacturing plant weren’t interrupted, plant spokesperson Biance Johnson said.
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The raid is the latest in a series of sweeping ICE operations as part of President Donald Trump’s mass deportation agenda, which saw immigration officers raid farms, construction sites, restaurants and auto repair shops.
The US labour force lost more than 1.2 million immigrants from January through July, which includes legal and illegal immigrants, according to the Pew Research Centre, citing preliminary census data.