Amid a recent surge in arrests of immigrants allegedly living in the country illegally, some raids by U.S. Immigration and Customs Enforcement have drawn quiet concern from Republicans in Congress who largely back President Donald Trump’s mass-deportation project.

Immigration and Customs Enforcement agents — often dressed in plainclothes — are now arresting immigrants at courthouses nationwide, sometimes moments after their hearings end. Why it matters: The courthouse crackdown is part of a sweeping Trump administration effort to fast-track removals and increase the number of deportations this year — a strategy that's dramatically expanding who gets targeted and how.

Arrests by Immigration and Customs Enforcement during President Trump's second term topped 100,000 this week, as federal agents intensified efforts to detain unauthorized immigrants in courthouses, worksites and communities across the U.S., internal government data obtained by CBS News shows.

Many of the people arrested at appointments had been released under a program for those deemed not to be threats to public safety.

The latest arrests suggest tensions are increasing ahead of the weekend, when more demonstrations are planned.

Former officials said the Trump administration’s push for the agency to detain record numbers of undocumented immigrants increases the chances of mistakes.

In emails sent to rank-and-file agents last weekend, leaders suggested that agents get creative to detain more suspects.

As Donald Trump revamps his promised nationwide crackdown on immigration, federal authorities are taking more aggressive measures to detain immigrants.

Protests against President Donald Trump's immigration crackdown and ICE raids have emerged across the U.S., including in Iowa. Here's what to know.

The motion is part of a lawsuit challenging the administration's expansion of the process which allows the government to quickly expel migrants.

Immigration and Customs Enforcement agents are starting to more aggressively target agriculture and food processing facilities around the country as reports over the past week from (Nebraska), New Mexico and California also highlight.