Of the 317 South Korean workers who were arrested by U.S. immigration authorities in September at a battery plant construction site in the state of Georgia and sent home the following week, approximately 50 have returned to work in America.

Speaking to one of the engineers, identified by the surname Kim, ABC News said Friday that roughly 50 engineers had reentered the U.S. as of November 15.

An attorney representing the workers said more than 100 of them had their B-1 business visas reinstated without reapplying.

Kim said over 200 of the workers were preparing to sue U.S. Immigration and Customs Enforcement(ICE) over allegations of unlawful policing, racial profiling, human rights violations, excessive force and unlawful arrest.

Seoul’s foreign ministry told ABC News that South Korea and the U.S. are still working to fix the visa system between the two countries.

While declining to comment on details of individual visas, the U.S. State Department said it is implementing President Donald Trump’s commitment to the reindustrialization of America by facilitating legitimate business travel and foreign direct investment.

On September 4, ICE and other related agencies raided the construction site of a Hyundai Motor-LG Energy Solution battery plant in Georgia and arrested 475 workers, including the 317 South Koreans.