U.S. immigration agents carrying out an enforcement push in North Carolina's largest city have arrested more than 130 people and are now moving into an area around the state's capital city.

The immigration sweep that started in Charlotte over the weekend comes on the heels of similar operations in Los Angeles and Chicago, as crackdowns — and the threat of crackdowns — develop in cities nationwide.

It's the latest phase of Republican President Donald Trump 's mass deportation efforts that have sent the military and immigration agents into Democratic-run cities.

Here’s what to know:

The Department of Homeland Security says it's focusing on the southern state because of so-called sanctuary policies that limit cooperation between local authorities and immigration agents.

Most county jails in North Carolina have long helped federal officials by holding arrested immigrants so agents can take custody of them. But a few jails resisted until a state law effectively made it mandatory last year.

Politics could also be playing a role. The state's governor is a Democrat and so are the mayors of Charlotte and Raleigh, the state's two biggest cities.

So far, the U.S. Customs and Border Protection agency says more than 130 people have been arrested in Charlotte.

It says those arrested include people with criminal records. But the agency has offered few other details.

Charlotte has been in the middle of nationwide debates over crime and immigration, most notably after the fatal stabbing this summer of a Ukrainian refugee on a commuter train. While the suspect was from the U.S., the Trump administration repeatedly accused Democrats of backing soft-on-crime policies.

One of the nation's fastest growing regions, Charlotte alone has more than 150,000 foreign-born residents.

The mayor of Raleigh on Tuesday said there have been “confirmed sightings” of Border Patrol officers operating in the county that's home to the state’s capital city and some nearby cities.

Mayor Janet Cowell earlier said she doesn’t know how large or how long the operation might be, and immigration authorities haven’t given details. Like the mayor in Charlotte, Cowell says crime is lower in Raleigh this year compared to a year ago.

Republican leaders say the increased enforcement is needed to restore safety to Charlotte.

But the state’s governor, Democrat Josh Stein, says it's increasing fears and dividing residents. He says Border Patrol agents are picking up random people and targeting them based on their skin color.

Homeland Security leaders are preparing to send border agents into New Orleans and southeast Louisiana in just a few weeks, according to documents obtained by The Associated Press and three people familiar with the operation.

The two-month immigration crackdown dubbed “Swamp Sweep” is expected to begin in earnest on Dec. 1.

Department officials declined to comment on the operation.

In Memphis, Tennessee, where National Guard troops have been patrolling neighborhoods and commercial areas since October, a judge this week blocked their deployment as part of Trump’s crime-fighting operation.

The judge, however, is giving the government five days to appeal. Democratic state and local officials sued to stop the deployment, saying it can only happen during civil unrest when there’s a rebellion or invasion.