US authorities conducted a predawn Monday raid on the Washington-area home of Democratic Representative Ilhan Omar as part of an ongoing investigation, the Justice Department said.

The raid followed a criminal fraud investigation into the Somali-born lawmaker’s immigration paperwork, which was filled out by her late father when she was a child, Fox News Digital reported, citing unidentified sources.

“Today in the Washington, DC area, Homeland Security Investigations executed a judicially authorised search warrant secured by the Department of Justice. This enforcement action is part of an ongoing federal investigation,” a Department of Justice spokesperson said in an email.

A representative for Omar did not immediately respond to a request for comment.

The raid came a little more than three weeks before the Nov 3 midterm elections, when President Donald Trump’s Republicans will be trying to defend their thin majorities in the US Congress.

Omar has been a frequent target of political insults from Trump, who has cast the Somali American community as a threat to Minnesota in a burst of anti-Somali and anti-Muslim rhetoric.

‘Creepy obsession’

Omar, an outspoken critic of Trump, has called his focus on her an “unhealthy and creepy obsession”.

Last week, Trump called Democratic candidate for US Senate from Michigan Abdul El-Sayed, who is Muslim, a “RADICAL Extremist” and “Terrorist Sympathiser” while offering support for the Republican candidate, Mike Rogers.

Civil rights advocates have criticised the Republican president’s rhetoric towards minorities and immigrants, including when he previously called Somalis “garbage”.

Trump in February said that Omar and Democratic Representative Rashida Tlaib of Michigan, who is also Muslim, should be “institutionalised” and sent back to “where they came from”.

Both lawmakers had criticised Trump during his State of the Union address as he touted his administration’s hard-line immigration crackdown and its immigration enforcement actions.

The progressive lawmaker has repeatedly said she and her family have faced death threats, which she attributes to “hateful political rhetoric”, especially from Trump.

Last month, a Minnesota man who squirted vinegar on Omar was sentenced to one year and two months in prison after pleading guilty to assaulting a federal official.

Anthony James Kazmierczak admitted to attacking Omar because he disagreed with her progressive political views.