Nearly half of all immigrants in the Minneapolis-St. Paul Twin Cities were found to have committed some form of immigration fraud during a recent sweep by authorities with the Department of Homeland Security, officials revealed Tuesday.

“Officers encountered blatant marriage fraud, visa overstay, people claiming to work as businesses that can’t be found, forged documents, abuse of the H1B visa system, abuse of the F1 visa, and many other discrepancies,” US Citizenship and Immigration Services (USCIS) director Joseph B. Edlow told reporters Tuesday.

Officials didn’t point to a specific group, but the Twin Cities has seen a massive uptick in Somali refugees and immigrants in recent years — with more than 82,000 from the East African country living in Minnesota.

USCIS visited 1,000 homes across Minneapolis and St. Paul in the last two weeks and found “nearly 50%” of inhabitants were engaged in some form of immigration fraud.

“Our officers found indications of fraud, non-compliance or public safety and national security concerns,” Edlow said. “What they found should shock all of America.”

The operation – dubbed Twin Shield, and carried out with the help of ICE – began on Sept. 13 and concluded this week, with Edlow calling it a “success” that could soon be repeated in cities across the country.

“This is the first of many,” Edlow said. “Any city should be prepared to be the site for an operation of this magnitude.”

Questions about the influx of migrants to the Twin Cities — particularly Somali migrants — have been in the national spotlight since claims emerged that liberal firebrand Rep. Ilhan Omar — a naturalized US citizen from Somalia — married her own brother to get him US citizenship.

Omar has denied the reports, which originated in conservative blogs as she was running for state office in 2016, calling them “false and ridiculous.”

It remains unclear how many people were detained in the recent federal operation — officials would only disclose that “multiple” had been taken into custody, explaining that it was too early to give an accurate number.

The Twin Cities were chosen because the “data” showed it as a hotspot for “manipulation and misuse of the immigration system,” officials said, with cases of marriage fraud found to be a particular problem.

In one incident, investigators encountered a Kenyan immigrant who paid just $100 for a fake death certificate in his wife’s name so he could marry his way into the US. The trouble is, his wife was alive and well, and found with their five kids in Minneapolis.

“Incidentally, he has another wife living in Sweden with whom has an additional three children,” Edlow said.

Another migrant found living in the Twin Cities was the son of a “known or suspected terrorist on the no-fly list,” and had made numerous attempts to commit marriage fraud before being caught in the operation, according to officials. He is now in custody for deportation.

A third person conned an elderly American woman into marriage – and while the bogus couple have since divorced, officials said she “lives in fear” of retaliation from the conman.

“I want the American people to know that we are declaring war on immigration fraud,” Edlow said. “We have a responsibility to keep this system legitimate.”

“What has been uncovered by these diligent officers over the past two weeks, that’s only the tip of the iceberg.”

Minnesota has sizable immigrant populations from countries like India, Vietnam, and Mexico, but its Somali residents have been a flashpoint for years.

The first refugees from Horn of Africa started arriving in the 1990s as Somalia descended into a violent civil war and famine.

While most are law-abiding asylum seekers – former Hennepin County Sheriff Rich Stanek previously told Fox News “95%” are “good people” who want “to raise their families” – a minority have caused an outsized negative impact with rampant crime and gang activity.

Credit card fraud and burglaries have been chief among those crimes – while in some extreme cases recruitment to overseas terror organizations like ISIS have been encountered.