Horrific footage shows US police officer thrown down Capitol building stairs and beaten by pro-Trump rioters

Warning this video contains scenes some people may find disturbing

Horrific new footage from Thursday's Capitol riots in the US has surfaced showing a Donald Trump supporter grabbing a police officer before pulling him down some stairs where he's beaten with an American flag.

In the video shared to Twitter by CNN's Bill Weir, a rioter wearing a white hat and backpack is seen pulling the officer down from where he is standing onto the Capitol building staircase. 

The officer is then stomped on by 'MAGA' supporters and bashed with a US flag. The identity of the officer and his condition is unknown. 

Pro-Trump rioters stormed the US Capitol building on Thursday resulting in the deaths of five people, including Capitol police officer Brain Sicknick. Dozens have been criminally charged in connection with the riot.

Twitter users were shocked by the footage, many wondering why tear gas wasn't used to clear rioters as it was used during Black Lives Matter (BLM) protests. 

"A couple of dozen tear gas grenades would have cleared those assholes out in five minutes. Where were the high decibel crowd control systems like BLM protests?" one wrote.

"At this moment I am so embarrassed and ashamed to be an American. If you told me five years ago this is where our country would be I would have never believed you," said another.

Democrats plan to introduce an article of impeachment against US President Donald Trump on Monday (local time) for inciting violence in the form of the Capitol riots.