SAVANNAH, Ga. (AP) -- U.S. immigration authorities on Thursday raided the sprawling site where Hyundai manufactures electric vehicles in southeast Georgia, shutting down construction on an adjacent factory being built to produce EV batteries.

The operation targeted one of Georgia's largest and most high-profile manufacturing sites, touted by the governor and other officials as the largest economic development project in the state's history. Hyundai Motor Group began manufacturing EVs a year ago at the $7.6 billion plant, which employs about 1,200 people.

U.S. Immigration and Customs Enforcement spokesman Lindsay Williams confirmed that federal authorities were conducting an enforcement operation at the 3,000-acre (1,214-hectare) site west of Savannah. He said agents were focused on the construction site for the battery plant but gave few other details.

Georgia State Patrol troopers blocked roads to the Hyundai site. They were dispatched to assist federal authorities in serving "a criminal search warrant," the Georgia Department of Public Safety said in a statement.

Video posted to social media Thursday showed workers in yellow safety vests lined up as a man wearing a face mask and a tactical vest with the letters HSI, which stands for Homeland Security Investigations, tells them: "We're Homeland Security. We have a search warrant for the whole site."

"We need construction to cease immediately," the man says. "We need all work to end on the site right now."

President Donald Trump's administration has undertaken sweeping ICE operations as part of a mass deportation agenda. Immigration officers have raided farms, construction sites, restaurants and auto repair shops.

The Pew Research Center, citing preliminary Census Bureau data, says the U.S. labor force lost more than 1.2 million immigrants from January through July. That includes people who are in the country illegally as well as legal residents.

In addition to making electric vehicles at the site facing Interstate 16 in Bryan County, Hyundai has also partnered with LG Energy Solution to build the battery plant. It's slated to open sometime next year.

The joint venture, HL-GA Battery Company, "is cooperating fully with the appropriate authorities," the company said in a statement. "To assist their work, we have paused construction."

Operations at Hyundai's EV manufacturing plant weren't interrupted, said plant spokesperson Bianca Johnson.

"This did not impact people getting to work," Johnson said in an email. "Production and normal office hours had already begun for the day" when authorities shut down access.