Senators at Donald Trump's second impeachment trial have been shown new dramatic and graphic video of an attack by his supporters at the US Capitol.

Using Mr Trump's own words and tweets against him, Democrats prosecuting the case argued he had acted as "inciter-in-chief" on the day and beforehand.

In at times emotional testimony, impeachment managers methodically pieced together the violence.

Unreleased security footage also showed how close rioters came to US lawmakers.

Police inside were shown desperately ushering politicians to safety, sometimes within yards of rioters breaking their way into the building's chambers.

In frenzied audio, security officials were heard asking for support and telling how crowds were using weapons like bats and tear gas against them.

Delegate Stacey Plaskett, presenting evidence, argued that the former president had "deliberately encouraged" the violence and "put a target on the backs" of senior figures, including his own Vice-President Mike Pence.

The Capitol building was stormed on 6 January after thousands gathered in support of false claims that widespread fraud denied Mr Trump victory in last November's presidential election.

Five people died, including a Capitol police officer, as a mob breached the building where the election result was being certified.

Mr Trump's lawyers will present the case for the defence later this week, but have already argued the trial against him is politically motivated and unconstitutional.

A two-thirds majority is required to convict Mr Trump in the evenly split 100-seat Senate, but an acquittal looks likely as the vast majority of Republican senators have remained loyal to him so far.

If convicted, he could be barred from holding office again.

What happened on Wednesday?

After a procedural vote about the constitutionality of proceedings on Tuesday, senators sat through the first day of evidence in the trial in which each side has 16 hours to present their case.

Lead prosecution manager Jamie Raskin argued Mr Trump was no "innocent bystander" to last month's violence having "praised, encouraged and cultivated" it for months before.

Managers used social media posts and clips of Mr Trump to illustrate how he spent weeks pushing a "Big Lie" that the election had been stolen from him.

They forensically dissected footage of the 6 January speech they say he used to "inflame" supporters further before directing them to march to the Capitol.

Screenshots from pro-Trump websites were shown as evidence that radicals in his support base were emboldened by his rhetoric to pre-plan the attack and spoke openly about their ambitions for violence against lawmakers.

Previously unreleased security footage showed how rioters, including some in body armour, violently breached the building and sought out those who had gathered to certify the election result.

In one clip, Republican senator and former presidential candidate Mitt Romney was seen being ushered to safety by a Capitol police officer.

Another video showed Vice President Pence and his family being evacuated amid chants by some in the crowd to "hang" him for refusing to object to certifying the result.

In another sequence, staffers of Nancy Pelosi were heard whispering in hiding as rioters breached her office and called out "Where are you, Nancy" in search of the House Speaker.

Some of the footage shown on Wednesday was graphic. Mobile phone footage showed a Trump supporter being shot dead as she tried to enter the House of Representatives' lobby and another video showed a riot police officer screaming out in pain as he was crushed in a doorway by the mob.

Those arguing the case repeatedly appealed to the emotions of senators, who act as jurors in the case, about their own experiences on the day.

"You were just 58 steps away from where the mob was amassing," Congressman Eric Swalwell told them.

"These attackers stood right where you are...They desecrated this place and literally the president sat delighted, doing nothing to help us," Representative David Cicilline said, telling Republicans: "We have to make this right, and you can make it right."

As proceedings resumed after a dinner break, impeachment managers focused on Mr Trump's failure to condemn and call-off his supporters as the violence unfolded.

"President Trump left everyone in this Capitol for dead," Representative Joaquin Castro said.

What will happen next?

Democrats will continue to argue their case for conviction on Thursday, before Mr Trump's team take to the stand in his defence.

His lawyers have already outlined their argument that the case against him is unjust and maintain he did not encourage violence from supporters.

Arguments are expected to run through until the weekend when senators will get a chance to ask questions.

It is unclear if the impeachment managers will then extend the timetable by requesting witnesses be called or subpoenaed - although Mr Trump has already declined to voluntarily testify.

Lawmakers on both sides are said to favour a quick trial and a Senate vote on whether to acquit or convict Mr Trump could be held early next week.

Only six Republicans voted that the trial was constitutional earlier this week - far short of the 17 that would be required to vote with Democrats to achieve a conviction in the final vote.

Maine Senator Susan Collins described the House's presentation on Wednesday as "riveting" and "compelling" and said "you could have heard a pin drop" during it.

"After the American public sees the full story laid out here... I don't see how Donald Trump could be re-elected to the presidency again," another Republican, Senator Lisa Murkowski, told reporters.