Washington DC has mobilised the National Guard ahead of planned protests by President Donald Trump’s supporters in connection with the congressional vote expected on Wednesday to affirm Joe Biden’s election victory.

Mr Trump’s supporters are planning to rally on Tuesday and Wednesday, seeking to bolster the president’s unproven claims of widespread voter fraud.

“There are people intent on coming to our city armed,” DC acting police chief Robert Contee said.

A pro-Trump rally in December ended in violence as hundreds of the president’s supporters, wearing the signature black and yellow of the Proud Boys faction, sought out confrontations with a collective of local activists attempting to bar them from Black Lives Matter Plaza, an area near the White House.

On Monday, Metropolitan Police Department officers arrested the leader of the Proud Boys, Henry Tarrio, 36, after he arrived in Washington ahead of this week’s protests.

Mr Tarrio was accused of burning a Black Lives Matter banner that was torn down from a historic black church in downtown Washington during the December protests.

A warrant had been issued for Mr Tarrio’s arrest for destruction of property, police said.

He was also facing weapons charges after officers found him with two high-capacity firearm magazines when he was arrested, a police spokesman said.

Mr Trump has repeatedly encouraged this week’s protests and hinted that he may get personally involved. Over the weekend, he retweeted a promotion for the rally with the message, “I will be there. Historic Day!”

The protests coincide with Wednesday’s congressional vote expected to certify the Electoral College results, which Mr Trump continues to dispute.

Election officials from both political parties, governors in key battleground states and Mr Trump’s former attorney general, William Barr, have said there was no widespread fraud in the election.

Nearly all the legal challenges from Mr Trump and his allies have been dismissed by judges, including two rejected by the Supreme Court.

Now with downtown DC businesses boarding up their windows, mayor Muriel Bowser has requested a limited National Guard deployment to help bolster the Metropolitan Police Department.

During a press conference on Monday, Ms Bowser asked that local area residents stay away from downtown DC, and avoid confrontations with anyone who is “looking for a fight”.

But, she warned, “we will not allow people to incite violence, intimidate our residents or cause destruction in our city”.

According to a US defence official, Ms Bowser put in a request on New Year’s Eve to have Guard members on the streets from Tuesday to Thursday to help with the protests.

The official said the additional forces will be used for traffic control and other assistance but they will not be armed or wearing body armour.

Some 340 DC National Guard members will be activated, with about 115 on duty in the streets at any given time, said the defence official, who provided details on condition of anonymity to discuss internal deliberations.

The defence official said that there will be no active duty military troops in the city, and the US military will not be providing any aircraft or intelligence.

The DC Guard will provide specialised teams that will be prepared to respond to any chemical or biological incident.

The National Park Service has received three separate applications for pro-Trump protests on Tuesday or Wednesday, with estimated maximum attendance at around 15,000 people, said Park Service spokesman Mike Litterst.

Organisers plan to rally on Tuesday evening at Freedom Plaza and again all day Wednesday on the Ellipse, including a 1pm Wednesday march to the Capitol.