A South Korean worker who was detained in a huge immigration raid last week at the site of a U.S. car battery project involving Hyundai Motor and LG Energy Solution in the U.S. state of Georgia, hugs a family member in the long term parking lot at the Incheon International Airport in Incheon, South Korea, September 12, 2025. REUTERS/Kim Soo-hyeon
A chartered plane transporting South Korean workers who were detained in a huge immigration raid last week at the site of a U.S. car battery project involving Hyundai Motor and LG Energy Solution in the U.S. state of Georgia, arrives at the Incheon International Airport in Incheon, South Korea, September 12, 2025. REUTERS/Kim Soo-hyeon

By Hyunjoo Jin and Joyce Lee

INCHEON, South Korea (Reuters) -South Korean workers who returned home on Friday after being detained for a week by U.S. immigration authorities described their horror over the raid at their workplace in the state of Georgia and their relief at being reunited with their families.

"It was like a military operation," said one of the workers of the September 4 raid at the car battery plant that is owned by Hyundai Motor and LG Energy Solution, adding the authorities had deployed across the site in less than 10 minutes.

Like many others who spoke to Reuters after their charter plane landed at Incheon airport, he declined to give his name due to the sensitivity of the matter.

A second worker said U.S. government agents had arrived at the site in helicopters and armoured vehicles and had separated workers according to visa type, arresting those on the ESTA visa-waiver programme or with a B-1 business traveller visa.

Workers' phones were confiscated, and some were unable to inform their families back home until their eventual release.

In total, some 475 workers - including more than 300 South Korean nationals - were detained at the plant, in the biggest single-site operation conducted by the U.S. Department of Homeland Security (DHS) in its history.

U.S. officials said the workers were engaged in activities beyond the scope of their visa authorisation or had overstayed their visas.

RELIEF AND ANGER

"I am really relieved now," said Hwang In-song, the brother of a detained engineer. "I was so worried and couldn't sleep well for a week."

The anxiety of the detainees and their families increased further when diplomatic wrangling over the terms of their release delayed their departure.

"I didn't know when I would actually be able to leave. That was the hardest part," said one of the workers.

Asked about life at the detention center in Folkston, Georgia, where they were held, he said: "It was the worst."

Others complained about the quality of the food and said the water smelt of bleach.

The United States Immigration and Customs Enforcement did not immediately respond to Reuters' questions about the allegation of poor conditions at the facility.

The wife of one subcontractor engineer, who gave only her surname Kim, said her husband had been arrested on his first day of work at the site, adding she had believed his B-1 visa status allowed him to work as a supervisor.

She said she now feared that it would be hard for him to get U.S. visas and to make business trips, adding: "I am worried this will ruin his career."

South Korean officials said on Thursday that U.S. President Donald Trump had encouraged the released South Korean workers to stay in the United States and train Americans.

"I don't think anyone wanted to stay... After going through this, I am not sure whether we would go back," said Jang Young-seon, who held a B-1 visa.

The video and photos of workers shackled at the wrists, waist and ankles sent shockwaves through South Korea, a key Asian ally of the United States.

"I was furious to see an ally treating my brother like a criminal," said Jang's brother Jang Young-eun at the airport.

(Reporting by Hyunjoo Jin and Joyce LeeEditing by Gareth Jones)