Protesters across the U.S. are calling for "no work, no school, no shopping" as part of a nationwide strike on Friday to oppose the Trump administration's immigration crackdown.

The demonstrations are taking place amid widespread anger over the killing of Alex Pretti, an intensive care nurse who was shot multiple times during an immigration enforcement operation in Minneapolis.

The death heightened scrutiny over the administration's tactics after the Jan. 7 death of Renee Good, who also was fatally shot during an immigration enforcement operation in Minneapolis.

"The people of the Twin Cities have shown the way for the whole country — to stop ICE's reign of terror, we need to SHUT IT DOWN," said one of the many websites and social media pages promoting actions in communities around the United States.

Some schools in Arizona, Colorado, and other states preemptively canceled classes in anticipation of mass absences.

Many other demonstrations were planned for students and others to gather at city centers, statehouses, and churches across the country.

Just outside Minneapolis, hundreds gathered in the frigid cold early Friday at the Bishop Henry Whipple Federal Building, the site of regular protests in recent weeks.

After speeches from clergy members, demonstrators marched toward the facility's restricted area, shouting at a line of Department of Homeland Security agents to "quit your jobs" and "get out of Minnesota."

Much of the group later dispersed after they were threatened with arrest by local law enforcement for blocking the road.

Michelle Pasko, a retired communications worker, said she joined the demonstration after witnessing federal agents stopping immigrants at a bus stop near her home in Minnetonka, Minnesota, a suburb of Minneapolis.

"They're roaming our streets. They're staying in hotels near our schools," she said.

"Everyone in this country has rights, and the federal government seems to have forgotten that. We're here to remind them."

In Michigan, dozens of students walked out of Friday morning classes at Groves High School in Birmingham, north of Detroit.

The students braved the zero-degree temperatures and walked about a mile to the closest business district, where a number of morning commuters honked horns in support.

"We're here to protest ICE and what they're doing all over the country, especially in Minnesota," said Logan Albritton, a 17-year-old senior at Groves.

"It's not right to treat our neighbors and our fellow Americans this way."

Abigail Daugherty, 16, organized the walkout at Collins Hill High School in Suwanee, Georgia, on Friday.

"For years, I have felt powerless. And seeing other schools in the county being able to do this, I wanted to do something," the sophomore said.

Numerous businesses announced they would be closed during Friday's "blackout."

Others said they would be staying open, but donating a portion of their proceeds to organizations that support immigrants and provide legal aid to those facing deportation.

Otway Restaurant and its sister Otway Bakery in New York posted on social media that its bakery would stay open and 50% of proceeds would go to the New York Immigration Coalition.

The restaurant remained open as well.

"As a small business who already took a huge financial hit this week due to the winter storm closures, we will remain open on Friday," it posted.

In Maine, where Republican Sen. Susan Collins announced that ICE is ending its surge, people gathered outside a Portland church on Friday morning, holding signs that said "No ICE for ME," a play on the state's postal code.

Grace Valenzuela, an administrator with Portland Public Schools, decried an "enforcement system that treats our presence as suspect."

She said ICE's actions brought "daily trauma" to the school system.

"Schools are meant to be places of learning, safety, and belonging. ICE undermines that mission every time it destabilizes a family," Valenzuela said.

Portland Mayor Mark Dion, a Democrat, spoke about the importance of speaking out in the wake of ICE's actions in the city.

"Dissent is Democratic. Dissent is American. It's the cornerstone of our democracy," Dion said.