Watch: Agents seen outside US Congresswoman llhan Omar's home

US immigration agents have searched the home of Minnesota Representative Ilhan Omar as part of a criminal investigation.

Homeland Security Investigations (HSI) agents "executed a judicially authorised search warrant" for the property in the Washington DC area, a US justice department spokesperson said.

The search "is part of an ongoing federal criminal investigation", the spokesperson said, but no further details were given. The US Congress is currently out of session and it is unclear if Omar was at home.

Omar, a Democrat and outspoken critic of President Donald Trump, described the search as "an attempt to target political enemies and weaponise federal law enforcement".

"For ten years, Trump has targeted me with baseless lies and smear campaigns," Omar said in a statement.

"This is just the latest escalation in his campaign of political intimidation. I will not be silenced."

Speaking to reporters on Monday, Trump said he had "nothing to do" with the justice department's investigation into Omar, while describing her as a "complainer" and a "terrible person".

The Republican president said of the Somali-born congresswoman: "She comes from a country that is a non-country.

"And then she comes over here and she complains about our Constitution."

Omar's communications director Jacklyn Rogers called Monday morning's raid "an outrageous abuse of power" by the Trump administration, adding: "The Congresswoman has done nothing wrong."

The nature of the criminal investigation remains unclear.

A BBC crew saw several agents at Omar's home, some carrying boxes to a van.

News of the search was first reported by Fox News, which said the investigation was about immigration paperwork filed by her late father when Omar was a child.

The timing of the raid - 22 days before the November midterm elections, which will decide the balance of power in Congress for the next two years - raised concerns from Omar's fellow Democrats.

The justice department has a longstanding policy of refraining from most enforcement action that is "likely to raise an issue or the perception" it was being brought for the purpose of affecting any election or to disadvantage a candidate.

The US House of Representatives Democratic Party leadership said in a statement that Omar had long been targeted with "vile personal attacks and baseless accusations" by Trump.

"Now, less than 30 days until the midterm election, his violent mass deportation machine has descended upon the home of a duly elected Member of Congress and her family," it said.

Omar's immigration records have been scrutinised in the past by Republicans. Earlier this year, fellow congresswoman Nancy Mace of South Carolina unsuccessfully filed a subpoena for her records.

Last month, Homeland Security Secretary Markwayne Mullin told a conservative podcaster "something is going to happen", making allegations of marital fraud against Omar.

Separately, White House border tsar Tom Homan told Fox News that Omar was being investigated for unspecified immigration violations.

"I will say it again so it's as clear as possible: I'm not at all worried about these investigations, because they are complete shams," she said in a campaign fundraising email.

Trump has previously suggested that Omar "should go back" to Somalia and that she should be deported. US citizenship is required to serve as a US House representative.

Omar has responded to Trump's insults and attacks describing them as an "unhealthy and creepy obsession".

The president has also singled out the Somali-American community. Last week, he wrote on social media that Minnesota "is being taken over by Somali immigrants" and said "the people of Minnesota must fight back".

"Nobody is above the law," said Minnesota congressman Tom Emmer. "We look forward to learning more details about this raid and investigation. ACCOUNTABILITY IS COMING!"

Omar is the first Somali American elected to the US House and she represents a district in the Minneapolis area. She and Michigan congresswoman Rashida Tlaib were the first Muslim women elected to Congress.

Omar won re-election two years ago with 74% of the vote.

Senior political leaders in Minnesota have criticised the search.

Governor Tim Walz said: "Americans see this for what it is - President Trump is abusing his power to go after political opponents weeks before an election."

Minnesota senator Tina Smith called it "a transparent attempt to interfere in our elections".