Hours into election night, with polls closing nationwide and votes being tallied, protesters clashed outside of the White House and pockets of other unrest around the US has been reported.

A protest in Washington, despite early reports of calm, reportedly started to turn as the night wore on.

CBS News reporter Christina Ruffini shared a video of what she called "some sort of smoke bomb" being used at the protest and said people were "just fighting." 

Pushing and shoving at the scene was broken up quickly. 

Other reports of violence have also surfaced. A man wearing a shirt supporting incumbent President Donald Trump challenged a protester to a fight in a situation that was diffused by police, according to the New York Times. 

Read more: LIVE US Election coverage 2020: Florida on a knife-edge | Election results and exit polls as we get them

A man was reportedly hit with a bat after shouting “all lives matter”. Bystanders broke up that confrontation, The New York Times reported. 

A police spokesman said so far, one arrest had been made as of just before 10pm local time. A man was arrested on charges of disorderly conduct, crossing a police line and resisting arrest. 

HeraldScotland: A protester in Washington (Photo: AP)A protester in Washington (Photo: AP)

In Chicago, one of the bridges near downtown’s Trump Tower had been lifted over the Chicago River - a common sight in recent months amid incidents of looting or unrest in the city. The move has been used to restrict access to downtown.

Video of the Illinois National Guard pulling into the city's downtown McCormick Place Convention Center circulated on social media Monday night, sparking concern among some. Yesterday the city's Office of Emergency Management and Communications said in a statement that the personnel were stationed in Chicago "to be ready to respond if needed" but that there were "no plans for them to be deployed."

Several protests were planned in neighborhoods throughout the city for Wednesday night.

Left-leaning demonstrators planned  Election Day protests for weeks. 

Some protesters are already gearing up for a longer, more sustained pushback. Organisers at ShutDownDC plan to host a lively event featuring live music, real-time election results and even salsa dancers the night of the election.

HeraldScotland: Protesters march in Portland (Photo: AP)Protesters march in Portland (Photo: AP)

But they plan for more aggressive actions as the week goes on depending on the outcome of the election, such as if President Donald Trump were to win reelection or to question the election outcome.

Mr Trump has said he would likely take legal action if he believes the election is conducted unfairly, especially in battleground Pennsylvania.

"As soon as that election's over, we're going in with our lawyers," he told reporters on Sunday.

Expecting a drawn-out battle, ShutDownDC organisers have plans to "disrupt business as usual for some of the institutions that are most complicit in Trump’s attack on Democracy."

And on Thursday, they plan to host a caravan of motorists, bicyclists and pedestrians. 

Outside of Washington, organizers are gearing up for protests around the country. Police are preparing, too. 

The Los Angeles Police Department announced a citywide tactical alert "to ensure sufficient resources to address any incidents that may arise as a result of Election Day activities."

The department added the alert was "not a result of any specific incident."

HeraldScotland: A man is detained in Los Angeles (Photo: AP)A man is detained in Los Angeles (Photo: AP)

Meanwhile organisers of the Women’s March have called for people to hold demonstrations around the country on election night  in which participants “shine a light on the process” by holding lanterns, flashlights, and candles, Vox reported. 

In Philadelphia, which has seen multiple days of unrest over the police shooting of Walter Wallace J., dozens of progressive organizations are planning “mass action" in the event of voter intimidation or mail-in ballot invalidation, the Philadelphia Inquirer reported.

More than 520 events have been organised nationwide by Protect the Results on November 4 and beyond if Trump either declares victory before all votes are counted or refuses to accept election results.