STORY: Last week's raid on a plant operated by Hyundai and LG in Georgia has South Korean workers in the U.S. running scared.
Reuters sources say large numbers are rushing home from facilities operated by LG Energy Solution.
It's the world's number two car battery maker, and has seven plants in the U.S., including four under construction.
The Hyundai raid last week saw 475 people detained, including over 300 Koreans.
Many of those held had been sent to the U.S. for construction work or equipment installation.
However, that kind of work is not permitted under visa waivers or business traveler visas.
One of the sources says workers at LGES plants who are in the U.S. on visa waivers have now been instructed by the firm to go home.
The company has reportedly told subcontractors to make contingency plans and hire local workers, concerned that the situation will hamper its operations in the U.S.
LGES wouldn't comment on that, but did say it had told all workers on business trips to the U.S. to head home or remain at their residences.
South Korean companies say they have struggled to obtain suitable visas for the workers needed at high-tech plants in the U.S., and have come to rely on a loose interpretation of visa rules.
South Korean media reports say Seoul and Washington will now discuss creating a new visa category to address the problem.
However, on Thursday, President Lee Jae Myung said the raid was likely to leave his country's businesses "hesitant" about investing in the U.S.
Meanwhile, a plane has arrived in Georgia to take home the workers detained in the raid.
It's expected to take off on Thursday (September 11) morning east coast time.
Seoul has asked that its nationals now be allowed to depart quickly and without handcuffs.