A free speech rally was organized by Team Save America, a right-wing group, following Twitter blocking the circulation of a New York Post story about Hunter Biden's emails and locking the Trump campaign account earlier this week.
Hundreds of counter- protesters turned up. Some held Black Lives Matter signs while others were dressed in black clothing, their faces covered and waving flags for violent left-wing group Antifa. Other protesters wore t-shirts claiming membership of the anti-fascist action group 161 Crew.
The Team Save America event ended up being called off within minutes of people arriving, before it even started. Violent clashes immediately broke out between the two sides leaving several in need of medical assistance.
The pro-Trump group planned to demonstrate outside of the United Nations Plaza before moving to Twitter’s Market Street headquarters.
Around midday, the group began assembling outside the plaza where they were greatly outnumbered by counter protesters who arrived with shields reading 'We keep us safe' that they used to then form a wall to prevent the San Francisco police from dispersing their march down Market Street.
Police tried to form a barrier to separate the two sides but failed to do so as fights broke out almost instantaneously.
Footage posted online showed rally organizer Philip Anderson being pushed by another man.
The organizer took the stage around 1 p.m. and was met with plastic water bottles and glass bottles hurtled at him over police barricades.
Anderson later posted graphic photos on social media of his bloodied mouth missing a tooth and wrote that 'Antifa attacked me for no reason'.
Another pro-Trump supporter, sporting a Trump 2020 t-shirt, was seen having a drink poured on him by a counter protester.
The man was later seen being wheeled off on a stretcher to an ambulance with his leg in a support.
One man was seen being attended to by another activist. The second man was pouring water into the injured one’s eyes to counter the effects of pepper spray deployed by cops into the crowd. It wasn't clear which group the men were affiliated with.
A man wearing a 161 Crew t-shirt was seen about to punch a demonstrator, while an Antifa flag was waving in the background.
Meanwhile, a San Francisco police officer was also seen injured on the ground being tended to by colleagues.
Cops were pouring water on his face after a demonstrator sprayed mace in his eyes.
The San Francisco Police Department confirmed three officers suffered non life-threatening injuries caused by pepper spray and caustic chemicals.
One of the officers was taken to a local hospital for treatment.
Not a single arrest has been made thus far.