ATLANTA (AP) — Buses carrying workers from South Korea who were detained last week in an immigration raid at a battery factory were traveling Thursday from a detention center in southeast Georgia to Atlanta, where a charter plane was waiting to take them home.

More than 300 Koreans were among about 475 workers detained during last week’s raid at the battery factory under construction on the campus of Hyundai’s sprawling auto plant west of Savannah. South Korea’s foreign ministry has said that a Korean Air Boeing 747-8i that arrived in Atlanta on Wednesday will depart at noon Thursday with the workers on board.

The workers had been held at an immigration detention center in Folkston, 285 miles (460 kilometers) southeast of Atlanta. South Korea’s Foreign Ministry confirmed that U.S. authorities have released the 330 detainees — 316 of them Koreans — and that they were being driven by bus to Hartsfield-Jackson Atlanta International Airport, where they will board a charter flight scheduled to arrive in South Korea on Friday afternoon. The group also includes 10 Chinese nationals, three Japanese nationals and one Indonesian.

South Korea’s President Lee Jae Myung called Thursday for improvements to the United States’ visa system, saying Korean companies will likely hesitate to make new investments in the U.S. until that happens.

South Korean officials have said they were negotiating with the U.S. to win “voluntary” departures for the workers, rather than deportations, which could make them ineligible to return to the U.S. for up to 10 years.

During a visit to Washington, South Korean Foreign Minister Cho Hyun met with U.S. Secretary of State Marco Rubio and told him that his people were left with “big pains and shocks” because the video of the workers’ arrests was publicly disclosed, the ministry said in a statement.

Cho called for the U.S. administration to help the workers leave as soon as possible — without being handcuffed — and to ensure they do not face problems in future reentry to the U.S., the statement said.