Protesters, including some dressed as Christmas elves, brandished signs reading “All I want for Christmas is my freedom back".
Bottles were thrown at officers as the protests in Trafalgar Square escalated after police began to break up huge crowds.
A planned Black Lives Matter rally has been cancelled amid fears of clashes between groups.
There are fears of clashes between anti-racism protesters and far-right activists during demonstrations on Saturday afternoon.
Around 50 people marched to Downing Street after observing a minute’s silence.
Crowds of anti-racism protestors have gathered in central London calling for justice for George Floyd, a Black man killed by police in Minneapolis on Monday.
Not only is it scary to think the men who catcalled me could assault me – what if they have coronavirus and pass it on? Kate Plummer writes.
Dozens of similar demonstrations are set to take place around the globe to call for a more robust response to the crisis.
The dead man and woman were known to each other, police have confirmed.
Protestors had originally planned to march on Central London.