ICE agents in Minneapolis kill second US citizen in January

US immigration, or ICE agents, shot and killed a US citizen in Minneapolis on Saturday, officials said, sparking fierce protests and condemnations from local leaders in the second such incident this month.

The Department of Homeland Security described it as an attack against federal officers.

But bystander videos showed the man, identified as 37-year-old Alex Pretti, who was licensed to carry a weapon, was holding a phone, not a gun.

Alex Pretti, a 37-year-old intensive care unit nurse, was against US President Donald Trump's immigration crackdown in Minneapolis and elsewhere in the US.

He was shot and killed by ICE agents on Saturday and his parents want answers.

"He (Alex) thought it (ICE) was terrible, you know, kidnapping children, just grabbing people off the street," said Pretty's father Michael Pretti. "He cared about those people, and he knew it was wrong, so he did participate in protests."

Accounts from authorities and witnesses differ.

One video shows ICE agents walking up to Pretti, forcing him back.

Another shows a number of ICE agents scuffling with someone who appears to be on the ground. Suddenly, shots ring out and agents disperse.

"This individual showed up to impede a law enforcement operation and assaulted our officers," said Homeland Security Secretary Kristi Noem. "They responded according to their training and took action to defend the officer's life and those of the public around him and I don't know of any peaceful protestor that shows up with a gun and ammunition rather than a sign."

Michael Pretti disputed Noem's statement, saying he had previously talked with his son about not engaging with ICE agents during protests.

He said Alex was licensed to carry a gun, he was disarmed during the scuffle and it was his phone that he was holding before he was shot.

A stunned Minneapolis community were out in force protesting the latest killing, two-and-a-half weeks after an ICE agent shot and killed Renee Good while she was in her car.

As protests became more boisterous, law enforcement resorted to shooting tear gas at crowds. An ad hoc memorial was set up in Minneapolis in tribute to Pretti.

Minnesota Governor Tim Walz, a Democrat, who has activated the National Guard, said he spoke to Trump.

He said the federal government cannot be trusted to carry out any investigation.

"As I said last week, this federal occupation of Minnesota, long ago stopped being a matter of immigration enforcement," said Walz. "It's a campaign of organised brutality against the people of our state. And today, that campaign claimed another life.

"I've seen the videos from several angles, and it's sickening. But I have a strong statement here for our federal government. Minnesota's justice system will have the last word on this. It must have the last word."

Trump hit back on social media, posting a picture of the gun that Pretti allegedly carried, accusing the Minnesota government of inciting an insurrection.