President Trump blasted counter protesters who descended on the Million MAGA March as 'Antifa scum' in a tweet on Saturday night

He encouraged cops 'don't hold back' after violent scenes erupted five blocks from the  White House at 8pm

Proud Boys and Trump supporters brawled with left-wing groups for several minutes before cops arrived

One man in his 20s was left with serious injuries after being stabbed in the back in an altercation 

Two police officers were also injured as they tried to subdue the groups

Fireworks and bottles were thrown at some Trump fans dining outside as tensions mounted 

Thousands had gathered in Freedom Plaza in Washington DC on Saturday for a pro-Trump 'Million MAGA March' in support of the president's unsubstantiated claims of widespread election fraud 

Taking part were far-right groups such as the Proud Boys and the Oath Keepers militia group 

Left-wing groups and self-proclaimed anarchists also showed up to confront Trump's supporters

Skirmishes of pushing and shoving broke out before police formed lines to separate the groups  

At least twenty arrests were made as of 10pm Saturday