WASHINGTON - Fear is running high among America's immigrant communities following arrests of hundreds of undocumented people in at least a half-dozen states by Federal agents who have become more aggressive under President Donald Trump, who campaigned for office with a vow to create a “deportation force,” according to media reports.

Federal officials insist they have not made fundamental changes in enforcement actions, and they deny stopping people randomly at checkpoints or conducting “sweeps” of locations where undocumented immigrants are common, according to The Washington Post.

But anxiety among immigrants spiked last week after the Immigration and Customs Enforcement (ICE) agency conducted a series of enforcement actions in large metropolitan areas, detaining hundreds of people in Chicago, Los Angeles, New York, Atlanta and other cities, as big protests took place on Saturday across the US, Amnesty International USA released a statement Saturday stating reports of the enforcement actions “raise grave human rights concerns.”

Members of the Congressional Hispanic Caucus demanded an immediate meeting with Thomas Homan, the acting head of ICE.

“These raids have struck fear in the hearts of the immigrant community as many fear that President Trump’s promised ‘deportation force’ is now in full-swing,” the lawmakers wrote in a letter to Homan.

"What’s certain is that even if ICE and other officials state this is business as usual, many immigrants find more persuasive the words and actions of Trump, whose political rise was propelled by anti-immigrant rhetoric, a vow to build a wall on the Mexican border and the promise to deport 3 million criminal immigrants," the Post said.

On Jan 25, five days after taking the oath of office, he issued an executive order titled “Enhancing Public Safety in the Interior of the United States.” Media attention focused on Trump’s call for an end to Federal funds for “sanctuary cities,” which do not automatically hand over illegal immigrants who come to the attention of local law-enforcement.

But the order also expanded the list of deportation priorities to include any non-citizen who is charged with a criminal offence of any kind, or who is suspected of committing criminal acts or being dishonest with immigration officials. The order gives broader leeway to ICE officers in deciding whether someone poses “a risk to public safety.”

For immigrant rights activists, the rules of engagement have clearly changed.

“Donald Trump has effectively created a way to deport individuals who have been accused, charged or convicted of anything from murder to jaywalking,” Angelica Salas, Executive Director of the Coalition for Humane Immigrant Rights of Los Angeles, was quoted as stating.

Fear of being detained or deported could lead many people to avoid going to work, school or public places in coming days, Salas said. She noted that one person detained by ICE last week had been at his job in a Target store.

“ICE wants us to believe they have removed a bunch of felons who were just plotting their next crime,” Salas said. “We know that ICE picked up some collaterals, people who happened to be nearby when officers arrived looking for someone else, and we think what we’ve just witnessed is how an emboldened ICE will operate.”

Several undocumented Los Angeles residents told The Washington Post that they did not want to be identified because they fear the Trump administration could use newspaper coverage to craft a list of deportation targets.

Under policies crafted during President Barack Obama’s second term, priority deportees included people who had been convicted of murder and other violent crimes as well as certain drug offences and gang involvement.

Obama’s policies called on ICE officials to avoid detaining, whenever possible, nursing mothers and those with serious medical conditions.

ICE last week has put out messages on social media suggesting that the enforcement actions were not part of a major crackdown ordered by Trump.

“ICE immigration enforcement actions target specific individuals according to the laws passed by Congress,” reads a tweet posted on Thursday by ICE.

ICE spokeswoman Sarah Rodriguez wrote in an email to The Washington Post: “ICE does not use checkpoints, nor do we use sweeping raids. We use targeted enforcement actions against specific individuals to make these arrests.”

Immigration rights activists are hoping to call attention to the actions of ICE while at the same time preventing full-scale panic among people who may be avoiding going to work or riding buses out of fear of being detained.

Meanwhile, thousands of Americans have taken to the streets to protest Trump administration's immigration policy and the arrests of hundreds of undocumented immigrants in several States this week.

About 2,000 demonstrators marched from outside the Federal Courts building in downtown Minneapolis to the University of Minnesota on Saturday afternoon to express solidarity with immigrants and Muslims.

The protesters denounced Trump’s now-frozen travel ban and his general view on immigration as State-sponsored hatred.

“It may take years or even decades, but the people always win,” one organiser told the crowd. “We are what makes America great.”

Many children also joined the “Walk of Love,” carrying homemade heart-shaped signs and red balloons.

Parents said they wanted their children to learn the importance of activism so they could defend their peers who might be targeted because of their ethnicity.

Elsewhere, hundreds of protesters spilled onto streets of New York City, blocking traffic and sidewalks to express their outrage at the nationwide immigration raids.

The demonstrators held signs that read “No Human is Illegal”, “No Ban. No registry” and “ICE Free New York City.”

In Washington, protesters gathered outside the White House on Saturday night to voice their concern about the criminalisation of immigrants.

“I’m an editor of a magazine, but also it feels like every aspect of my life is sort of affected by the new administration,” David Bonanno, a protester, told local media.

In the first week of his Presidency, Trump signed an executive order banning citizens of seven Muslim countries from entering the United States. 

A Seattle Federal judge blocked the order last month.

The US Court of Appeals for the Ninth Circuit in San Francisco, California, ruled on Thursday that the restraining order against Trump’s travel ban should stay in place while the judge further considers its legality.

Trump told reporters on Friday that he was considering signing a “brand new order” on immigration.