Dozens of conservative poll challengers converged on Detroit’s TCF Centre, the city's absentee vote-counting location, on Wednesday.
People banged on the Plexiglass windows demanding to be let into the room where more than 900 workers were finishing tabulating the city’s absentee ballots.
The angry crowd chanted “stop the count”.
“There’s a lot of scamming in there,” said Paul, a conservative poll challenger who didn’t want to give his last name.
Paul spent hours trying to get into the ballot counting room on Wednesday, but was among the dozens denied entry. He wore his frustrations on his clothes hanging a makeshift sign over his torso that read “Voter Fraud”.
While conservative poll watchers complained there weren’t enough Republicans participating in the ballot counting process, Detroit election officials maintained the maximum number of poll challengers, both Democrat and Republican, were already present inside.
The crowd began showing up after former Vice President Joe Biden started edging ahead of President Donald Trump in the vote count.
In an overnight speech, Mr Trump had already began casting doubt on the results and riling up his supporters.
"We were getting ready to win this election. Frankly, we did win this election," he said. "This is a fraud on the American public.”
As Mr Biden took the lead in Michigan on Wednesday morning, Mr Trump furthered his attacks.
“They are finding Biden votes all over the place — in Pennsylvania, Wisconsin, and Michigan. So bad for our Country,” tweeted the President.
Throughout the day, as absentee ballots in urban centres like Detroit, Wayne County and Flint came in, Mr Biden slowly stretched his lead to roughly two percentage points over Mr Trump.
But President Trump cast doubt on the result tweeting he had won Pennsylvania and Michigan, two of the closest of the state races this year.
“Additionally, we hereby claim the State of Michigan if, in fact, there was a large number of secretly dumped ballots as has been widely reported,” he tweeted without evidence to support his claims. His post was flagged by Twitter as a possible source of misinformation.
Trump campaign files lawsuits
On Wednesday, Mr Trump’s campaign filed a lawsuit in Michigan in hopes of stopping the counting of ballots.
"We have filed suit today in the Michigan Court of Claims to halt counting until meaningful access has been granted. We also demand to review those ballots which were opened and counted while we did not have meaningful access," the campaign said.
The lawsuit claims that a trained election challenger named Eric Ostergren from Roscommon County, a rural county in northern Michigan, was prevented from the absentee ballot counting process.
Michigan’s Secretary of State Jocelyn Benson called the lawsuit "frivolous" and said it does not have merit.
“It’s really an example of the type of misinformation designed to sow seeds of doubt among our voters about the integrity of our elections process which I fully stand behind,” Ms Benson said in an interview with CBS News.
The lawsuit did not deter election officials from continuing their vote counts.
President Trump’s campaign filed additional lawsuits Wednesday in Pennsylvania and Georgia. It is also demanding a recount in Wisconsin, where Mr Biden was declared winner.