A U.S. Customs and Border Protection raid at a Home Depot in Pomona has heightened concerns over the Trump administration’s targeting of immigrant workers and its potential to stymie rebuilding efforts after Los Angeles County’s devastating January firestorms.

Unmarked vehicles were the first to arrive outside the Home Depot on South Towne Avenue in Pomona around 8:30 a.m. Tuesday, where dozens of workers had gathered outside, according to witnesses and advocates.

An official with the Department of Homeland Security said 10 people were arrested in the enforcement action. Immigration advocates had previously estimated that as many as 25 were arrested.

Community members previously said the raid was carried out by Immigration and Customs Enforcement, but ICE officials said the agency did not participate in the activity and directed questions to U.S. Customs and Border Protection. A senior Department of Homeland Security official said in a statement to The Times that agents conducted an operation Tuesday targeting an individual with an active arrest warrant.

“During the operation, nine additional illegal aliens were encountered and taken into custody. Several of those apprehended had prior charges, including child abuse, assault with a deadly weapon, immigration violations, and DUI,” the official wrote.

Trump proposed a sweeping crackdown on immigrants in the nation illegally when he took office. Although various raids have occurred in cities across the country, there have been relatively few large ones reported in Southern California.

The raid comes three months after historic firestorms swept through areas of Los Angeles County, destroying more than 16,000 homes and setting up a historic rebuilding effort that will need extensive labor.

The National Assn. of Home Builders estimates that 41% of construction workers are immigrants. Experts told The Times in January that percentage is far higher in residential construction, in which wages are generally lower.

“Let’s say Trump can snap his fingers and wipe out every day laborer standing outside of Home Depot or Lowes, we’re not going to rebuild anytime soon,” said Tony Smith, a professor of political science and law at UC Irvine. “There are not enough skilled workers in the construction industry if you take out all the folks from across Latin America who are here doing it.”

The raid comes as Los Angeles is particularly reliant on the skills of day laborers in the wake of the Palisades and Eaton fires and targets a community of laborers who have felt safe congregating in Home Depot parking lots for decades. Immigration advocates immediately condemned the action, saying it targets law-abiding workers whose sole purpose is to earn wages to support themselves and their families.

When government-marked vehicles rolled onto the lot, some laborers suspected what was about to happen and ran, said Ron Gochez, a member of the Unión del Barrio, a political organization that started the Community Self-Defense Coalition.

The ICE spokesperson said in a statement that it “was not a part of the law enforcement activity in the city of Pomona, near a Home Depot. ICE does not conduct raids as part of its routine daily immigration law enforcement efforts. ICE’s enforcement resources are based on intelligence-driven leads and ICE officers do not target persons indiscriminately.”

More than 24 hours later, many of the workers’ family members still have no idea where their loved ones are being held.

“We have families who are now missing the main breadwinner for their home,” Gochez said. “These folks are not just working class, but really, really low income and so this puts their families in immediate danger of homelessness. It’s a clear example that demonstrates the Trump administration is lying when they talk about targeting criminals. They’re targeting people trying to look for work.”

On Wednesday morning, a group of abandoned cars belonging to the workers who were detained a day earlier sat in the Home Depot parking lot.

Some workers who were present during the raid but were not detained worked to contact their colleagues’ family members, but kept their eyes trained on cars entering the lot, concerned that immigration officials could return. The number of individuals who arrived outside the hardware store Wednesday in search of work was significantly fewer than usual, workers said.

Juan, who did not want to give his last name because of his immigration status, has been living in the United States for 23 years and has family back in El Salvador to support.

“We have to come out and work,” Juan said in Spanish. “If we are taken in, the family will be affected.”

Enrique Rios, who is from Mexico, said Tuesday’s action felt more selective than raids he’s heard about in which immigration officers arrive at a location and round up everyone they can.

“Immigration came and approached a specific group of people,” Rios said in Spanish. “They did not bother anyone else.”

L.A. County Supervisor Hilda Solis directed the Los Angeles County Office of Immigrant Affairs to connect with the Pomona Day Labor Center after the raid to “ensure those impacted receive the support and resources they need,” she said in a statement.

“While this remains a developing situation, I want to reaffirm my unwavering commitment to ensuring that all residents, regardless of their immigration status, are aware of and can exercise their constitutional rights,” she said.

The Pomona Police Department confirmed that an immigration action took place Tuesday, but said it had no prior knowledge of the raid and “did not collaborate with any federal agencies on their operation.”

Immigrant rights groups swiftly condemned the action.

Palmira Figueroa, a spokesperson for the National Day Laborer Organizing Network, said the actions of the federal government are not making the country any safer and aren’t aimed at removing criminals from the street. The raid shows they’re removing laborers who have families to feed, she said.

The president has vowed to carry out the largest deportation effort in U.S. history, going so far as declaring a national emergency at the southern border and deploying troops.

There are an estimated 11 million to 15 million undocumented immigrants in the U.S., including more than 2 million in California, according to the U.S. Department of Homeland Security.

“We know that the Trump administration has promised to go after immigrants and they have always made this promise to their allies,” Figueroa said. “We are trying to make the call out to American citizens to protect us. To those who hire immigrants workers, if they accept our labor they must also accept our humanity.”

Trump has issued executive orders limiting legal pathways for entering the U.S., bolstered efforts to seal off the U.S.-Mexico border, and promoted sweeps to round up and deport people who are not authorized to be in the United States.

Under the Trump administration, federal immigration officials have already conducted well-publicized operations in Chicago and New York.

Tuesday’s enforcement action was reminiscent of a longer operation this year in which U.S. Border Patrol agents conducted a three-day raid in rural parts of Kern County targeting day laborers and Latino farmworkers. The ACLU filed a lawsuit against the agency in February, saying the action amounted to a “fishing expedition” that indiscriminately targeted people of color who appeared to be day laborers and farmworkers.

Smith, the UCI professor, said he’s skeptical that the administration will be able to accomplish its deportation goals.

“Primarily, the Trump administration seems to be doing things in sort of a performative way,” Smith said. “They want to make a big splash and say they did something, but they don’t really follow through frequently. There’s a big question whether they actually have the capacity or the competency, or both, to do what they want.”

Angelica Salas, executive director for the Coalition for Humane Immigrant Rights, said undocumented immigrants are in the U.S. to seek a better life and do not pose any threat to their communities or the country.

“It’s shameful that the Trump Administration chooses to focus its enforcement activities on men and women looking for an honest day’s work,” Salas said in a statement. “We denounce these actions as they sow fear and confusion in the community and offer no solutions to our complex immigration system, which is in need of updates.”

Times staff writer Rachel Uranga contributed to this report.