US federal agents raid home of Democratic congresswoman and Trump critic Ilhan Omar

US federal agents searched the Washington home of Democratic congresswoman Ilhan Omar on Monday as part of a criminal investigation, officials said, marking a dramatic escalation in US President Donald Trump's confrontation with the outspoken lawmaker.

The search – three weeks before midterm elections that will decide control of Congress – was conducted by agents from Homeland Security Investigations (HSI), the investigative arm of US immigration enforcement, according to Fox News, citing sources familiar with the matter.

The cable network reported that the operation was linked to a criminal fraud investigation concerning immigration paperwork submitted on behalf of the Somali-born congresswoman by her late father when she was a child.

Trump's border enforcement chief Tom Homan told Fox News he was unwilling to give details ahead of any official announcement but confirmed that an "investigation was ongoing for a while" and that "there was a warrant executed this morning."

US media quoted the Department of Justice (DOJ) confirming that agents had carried out a court-authorised search in the Washington area, but officials did not identify Omar or disclose the nature of the investigation.

"Today in the Washington DC, area, Homeland Security Investigations executed a judicially authorised search warrant secured by the DOJ. This enforcement action is part of an ongoing federal investigation," a DOJ spokesperson told Fox News Digital.

The search reportedly began around 6:00am, with several agents wearing HSI jackets seen outside Omar's Washington residence, according to Fox News.

Omar, 44, is a leftist Democrat and fierce critic of Trump – particularly of his administration's sweeping crackdown on immigration.

The Republican president has repeatedly clashed with Omar, who came to the United States from Somalia as a child and has frequently been the target of his political attacks.

Rare offence

In September, Homan said that Omar was the subject of an ongoing criminal investigation, but again declined to provide details.

Omar said at the time that Homeland Security officials had not contacted her about any investigation, dismissing the allegations against her as politically motivated attacks.

There was no immediate public response from Omar to Monday's search. AFP sought comment from her office and the Trump administration.

Omar was first elected to Congress in 2018 and represents a district including Minneapolis, which is home to one of the largest Somali communities in the United States.

She is a member of the group of left-wing Democratic lawmakers known as "The Squad," who have been among Trump's most vocal opponents in Congress.

No charges against Omar were announced in connection with Monday's search.

Trump and his Republican allies have for years argued that non-citizens vote in significant numbers in US elections, which is a criminal offence punishable by imprisonment and deportation.

"What we are seeing is illegal aliens voting, non-citizens who are not eligible to vote voting, or those fraudulently registering to voters who are not eligible to vote," Attorney General Todd Blanche said last month.

"So, just to put a finer point on this, in under two years, this administration has charged nearly four times as many non-citizen voting cases as the last administration brought in four years, and we're currently investigating hundreds of cases across the country," he said.

But studies consistently find non-citizen voting to be too rare an offence to have affected the outcome of any federal election.

An election fraud database kept by the conservative Heritage Foundation – dating back decades – contains just 1,619 cases of election-related offences, of which non-citizen voting makes up a tiny 5.5 percent.

(FRANCE 24 with AFP)