President Donald Trump’s promised crackdown on illegal immigration has begun to take shape in San Diego County, as federal agents launched targeted operations to arrest undocumented immigrants and a wave of military troops got to work reinforcing U.

U.S. Immigration and Customs Enforcement (ICE) appear to be stepping up operations in San Diego County, as migrant communities remain on edge over President Donald Trump's pledge to carry out mass deportations.

Agents from U.S. Immigrations and Customs Enforcement, the FBI and the Drug Enforcement Administration have taken part in immigration raids across San Diego as President Donald Trump’s promised deportation crackdown

Immigrant rights groups are urging anyone who feels unsafe to know their rights in case they are stopped by a federal enforcement official.

At the heart of the discussion was to what extent city police are legally able to assist immigration officials under Senate Bill 54, a California law that restricts the role local law enforcement can play in immigration enforcement but also has allowances for working with federal officers to address violent criminals.

Border czar Tom Homan told NBC News that several people with criminal convictions were apprehended in Chicago.

One by one, an ICE attorney asked Partida to move the detainees’ cases to courts closer to their new locations. All of the people who were transferred had attorneys in San Diego, including some through a county program that represents people in local immigration custody for free.

Immigration and Customs Enforcement ... the U.S., including in Illinois, Utah, California, Minnesota, New York, Florida and Maryland. The cities where the arrests have taken place include Buffalo, New York, Chicago, St. Paul, Salt Lake City, San Francisco ...

Images of U.S. Immigration and Customs Enforcement raids across the country and in San Diego have some migrants afraid to leave their homes.

President Donald Trump has signed 10 executive orders on immigration and issued a slew of edicts to carry out promises of mass deportations and border security.

Agents from a handful of federal agencies combined to arrest more than 40 people in the country illegally early Sunday during a raid in Adams County, the local office of the Drug Enforcement Administration said.

Aurora, Colorado, which had been a focus for President Donald Trump during his campaign, will be the next city where an operation is conducted, sources told NBC News.