South Korean engineers describe being shackled and threatened in large US immigration raid in Georgia

More than 300 South Korean workers detained in one of the largest immigration raids of the Trump presidency this month say they were shackled, had guns pointed at them and were held in freezing, overcrowded cells before being allowed to return home without penalties.

The workers, who were in the US temporarily to help build an electric car battery plant run by Hyundai and LG, described helicopters and drones, armoured vehicles and immigration officers bursting into rooms and ordering them outside. Many said they were handcuffed, fitted with chains linking waist and ankles, and loaded onto buses bound for a detention centre in Georgia.

Several workers who spoke to the BBC, and who asked that only pseudonyms be used for fear of reprisals, said they had documentary proof of their visa status but were detained anyway. US officials initially said the workers had been in the country illegally on incorrect visas. After discussions between US and South Korean authorities, an agreement allowed the detained engineers to leave voluntarily without penalties, enabling them to return to work in the US in the future.

"I panicked and my mind went blank. I felt sick," said one engineer identified as Youngjin, who was in the US on a short-term assignment to train staff to operate specialised equipment. He said officers handcuffed him, attached chains to his waist and ankles, and took him to the Folkston ICE Processing Center.

Those detained described harsh conditions. Youngjin said he was locked in a room with 60 to 70 other people, was not given a blanket for the first two days and that the drinking water "smelt like sewage." Another worker, Chul-yong, said bunk beds were already occupied by the time he arrived and that some detainees tried to sleep on desks. Several described shackles so tight they could not touch their faces and said some people were visibly shaking from fear.

Company and government responses varied. LG said many of its employees who were arrested held different types of visas or were under the visa waiver programme. South Korean officials said the US deputy secretary of state had expressed "deep regrets" over the incident and that the US side acknowledged it "may have gone a bit too far," according to South Korea's chief trade negotiator.

Seoul said it is investigating potential human rights violations during the raid and has been working with US authorities to secure the workers' release and repatriation. Most of the workers returned to South Korea last Friday.

The detained engineers said they were primarily engaged in training and meetings, activities they believed were permitted by their visas or the visa waiver programme. One man who gave only his surname, Kim, said he believed his work fell within the scope of a B-1 business visa and questioned the logic of detaining hundreds of people without clarifying their roles.

The raid has prompted concern in Seoul because it comes shortly after a trade deal in which South Korean companies pledged roughly $350 billion in US investment. The incident has briefly strained relations between two close allies engaged in broader cooperation on trade and industrial investment.

Several detainees reported lingering psychological impacts after their return. Youngjin said he felt hollow when reunited with family and that some everyday smells now trigger panic attacks. Chul-yong said seeing himself on television, even without his face visible, made it difficult for family and friends to avoid recognising him, and that many workers may be reluctant to accept similar assignments in future despite the demand for their skills.

US immigration authorities have said the operation targeted people they believed were present on improper visas, but details on the decision-making and tactics used have prompted scrutiny from South Korea and calls for explanations. South Korean consular officials and lawyers were able to meet some of the detainees and assist in securing their release.

The detained workers were largely subcontractors and technical specialists involved in building high-tech battery manufacturing facilities intended to boost domestic production of electric vehicle batteries in the US. Such projects are part of a broader US policy push to attract foreign companies to manufacture more on American soil.

South Korean officials have said they will press for a full review of the raid and possible remedies for those affected. On the US side, officials have emphasised the need for foreign specialists to train US workers while also enforcing immigration laws, and they have begun talks with Seoul to resolve outstanding issues related to the incident.

The episode underscores tensions that can arise when immigration enforcement intersects with international business operations and highlights the vulnerabilities faced by foreign workers on short-term assignments. Workers and their families now face the immediate task of recovering from the experience while companies and governments weigh steps to prevent a recurrence.