By Doina Chiacu

WASHINGTON (Reuters) -Federal authorities conducted raids on Saturday in the banking hub of Charlotte, North Carolina, the Department of Homeland Security said, expanding its crackdown on illegal immigration to the U.S. South.

"We are surging DHS law enforcement to Charlotte to ensure Americans are safe and public safety threats are removed," DHS spokesperson Tricia McLaughlin said in a statement. "There have been too many victims of criminal illegal aliens."

DHS, which oversees U.S. Customs and Border Protection, did not provide details on the operation, including how many law enforcement officers took part or the number of people detained.

Charlotte Mayor Vi Lyles, a Democrat, and city commissioners on Saturday urged people to seek help, including from the Charlotte and Mecklenburg County Police Department, which is not participating in the federal raids.

"There are a number of organizations standing ready to assist individuals seeking legal guidance on immigration matters," the city officials said in a statement.

The expected raids caused fear and uncertainty in Charlotte because similar operations in other cities resulted in people without criminal records being detained, they said.

President Donald Trump, a Republican, has focused on ramping up immigration arrests in Democratic-led cities, with major pushes in recent months in Chicago, Los Angeles and Washington.

Local leaders earlier this week said they were informed that a CBP operation would start on Saturday. U.S. Representative Alma Adams, a Democrat, said on Thursday she was "extremely concerned" about Border Patrol and ICE personnel coming to Charlotte.

"Charlotte's immigrant community is a proud part of the Queen City, and I will not stand by and watch my constituents be intimidated or harassed," Adams posted on X.

Gregory Bovino, a U.S. Border Patrol official who has led Trump's aggressive crackdown in Chicago since September, responded to Adams that she and North Carolina Governor Josh Stein, a Democrat, "should learn the difference between an illegal alien & an immigrant."

Border Patrol agents in Chicago have helped increase immigration arrests, but protesters and some residents say they have used excessive force, including deploying tear gas in busy urban areas.

A Chicago-based federal judge barred immigration agents from using some aggressive tactics and ordered them to wear body cameras after videos cited in a lawsuit showed violent clashes with protesters.

(Reporting by Doina Chiacu; Editing by Sergio Non and Franklin Paul)