Donald Trump on Sunday warned darkly of the danger posed by Somali migrants in Minneapolis, a deeply segregated city that has the largest Somali-American community in the US.

“Here in Minnesota, you’ve seen first-hand the problems caused with faulty refugee vetting, with very large numbers of Somali refugees coming into your state without your knowledge, without your support or approval,” the Republican nominee told a rally in the solidly Democratic state, two days before the presidential election.

He then claimed: “Some of them [are] joining Isis and spreading their extremist views all over our country and all over the world.”

“Everybody’s reading about the disaster taking place in Minnesota,” he added, before claiming, falsely: “You don’t even have the right to talk about it.”

Trump has made warnings about refugees a staple of his stump speech, though he has most commonly targeted Syrians fleeing the five-year civil war that has devastated their country.

Unauthorized immigration in the US About 11.3 million people live in the US without legal papers, down from a peak of about 12.2 million in 2007. Net unauthorized immigration has been roughly even since 2010. According to 2012 figures, there are about 8 million unauthorized migrants either working or looking for work, or 5.1% of the labor force.

Since 2009, more Mexicans have been leaving the US than entering, likely due to a slow economic recovery since the recession and stricter border enforcement. Barack Obama has deported more than 2.5 million people, more than any other president. His executive orders protect at least 1.2 million people from deportations.

Three Somali Americans, two US citizens and one a lawful resident, pleaded guilty in June to trying to join the terror group Islamic State, or Isis. Law enforcement officials have said that more than 30 young men from Minnesota have left the county to join Isis or al-Shabaab, which operates in east Africa.

According to the 2010 census, more than 85,000 Somali Americans lived in the US with the largest concentration living in the Twin Cities. Despite integration campaigns by the community – a former refugee is poised to win office as a state lawmaker, for instance – the area remains one of the most racially segregated in the US.

The Republican nominee has said he would bar refugees from settling in places without the approval of local governments. A federal court ruled against Trump’s running mate, Indiana governor Mike Pence, in October, when he tried to block Syrian refugees from settling in his state.

In that decision, judge Richard Posner said Pence’s actions were discriminatory, and “the equivalent of his saying (not that he does say) that he wants to forbid black people to settle in Indiana not because they’re black but because he’s afraid of them, and since race is therefore not his motive he isn’t discriminating”.

In Minneapolis on Sunday, Trump said blocking refugees would be “the least [government] can do for you”.

“You’ve suffered enough in Minnesota,” he said, “and we will pause admissions from terror-prone regions until a full security assessment has been performed and until a proven vetting mechanism has been established.”

The US has some of the strictest vetting procedures in the world, requiring multiple stages of interviews with security agencies, background and health checks, and the process can last two years. Trump has not specified which countries he would bar migration from, nor many details of what he calls “extreme vetting”.

Trump argued that these methods would prevent terror attacks in the US, citing “the recent terrorist attack in St Cloud”. In that Minnesotan city, in September, a 20-year-old Somali American man stabbed eight people in a mall, before being fatally shot by a police officer.

The next day, leaders of the Somali community condemned the attack and the FBI said it was investigating it as a “potential act of terror”. It released few details.

“It’s horrible what they’re doing and if you want people to pour in Minnesota all you have to do is vote for Hillary Clinton,” Trump said on Sunday.

Somali Americans have become a target for domestic terrorists. In September, three members of a militia group were arrested for allegedly plotting to bomb an apartment building in Garden City, Kansas, with a number of Somali-American residents and where one apartment was used as a mosque.

The three men arrested could face life in prison.

According to the FBI complaint filed against the suspects, the men called themselves “the Crusaders” and Muslims “cockroaches”, and said that they wanted to “wake people up” with “a bloodbath”.