Question: (Note: I'm from the UK so whilst we get some news about America our news cycle isn't dominated by their affairs)

So, in 2020 there was the US elections, Biden won, but Trump is refusing to concede and is basically alleging there was massive voter fraud to prevent his win.

If you look at it from the perspective of a big Trump supporter, it looked like Trump might squeak out a win then suddenly there are a bunch of votes for Biden (aka postal votes) and then Biden wins comfortably, and the person you support alleges that there was massive voter fraud/irregularities and that's why he lost.

From their perspective it seems a compelling argument (though it is said to be wrong), Trump still has a lot of supporters and his base seem to be pretty devoted to him, plus they tend to be the people who are heavily armed and generally like to cause trouble.

Meanwhile throughout 2020, even during the whole pandemic situation, it seems that the USA has become a "riot friendly" country, the deaths of George Floyd and others at the hands of police officers have sparked massive protests across the country which in quite a few cases have turned into riots, with business being looted, property being damaged and further violence and deaths amongst those protesting.

I feel that the potent mix of Diehard Trump fans(with guns, who also generally don't seem to care about the COVID 19 pandemic) + Trump constantly claiming mass voter fraud, would result in violent protests and riots across the country amongst his fans.

Have there been any riots in the US attributed to the recent election results?

Answer: 
(Contra to Brian's answer) there were a few clashes, like this one in DC [on Nov 14](https://www.npr.org/2020/11/14/934957728/trump-supporters-descend-on-d-c-for-events-contesting-election-results):

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> The demonstrations unfolded peacefully for most of the day, but counterprotesters clashed with the president's supporters and violence erupted as night fell. Counterprotesters were seen overturning tables of vendors selling Trump merchandise, as well as stealing Trump hats and flags and setting them on fire, according to The Washington Post.
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> Two officers were injured and at least 20 people were arrested, according to the D.C. Mayor's Office. Of those arrests, four were for firearm violations, two for simple assault, one for an assault on a police officer and two for disorderly conduct, D.C. police told member station WAMU. Seven guns were recovered. It was not immediately clear if the guns belonged to Trump supporters or counterprotesters.
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> Scattered clashes turned violent around 8 p.m., when Trump supporters armed with batons and counterprotesters collided in a brawl five blocks from the White House, The Post reported, before police broke up the groups. A city fire official said a young man was transported to the hospital for serious injuries after he was stabbed in the back during the fight, according to the newspaper.
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But insofar these were much more limited than what some people feared.
There was a [violent riot](https://en.wikipedia.org/wiki/2021_storming_of_the_United_States_Capitol) in Washington, DC on January 6, 2021.

The BBC [reports](https://www.bbc.com/news/world-us-canada-55578092),

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> Trump supporters converged on Capitol Hill on Wednesday to express their rage over Joe Biden's victory in the election, wreaking havoc in Congress. Rioters were pictured vandalising congressional offices, and an aide to Speaker of the House Nancy Pelosi, Washington's top Democrat, reported a laptop was stolen.
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