A total of 76 people were arrested by local police after they took part in a protest at a shopping center in west London on Wednesday night.
The Metropolitan Police said on Thursday that "a group of protesters broke away from a larger group and attempted to force entry" into the shopping center, Westfield on Wednesday night.
Police said the protesters assaulted security staff and caused damage to property.
Police took a number of actions in response to this, including arresting 76 people on suspicion of public order offences, who have been taken to various police stations for questioning.
Local media reported about 600 people gathered in - and outside of the shopping center on Wednesday evening, they were there protesting the death of the black man Eric Garner, who was arrested and died in New York in July.
The protest was concluded, the police confirmed.
"We will always work with those that wish to demonstrate lawfully - as the majority of protesters did yesterday. However, we will not tolerate the small minority that offer violence or commit other criminal acts, such as that witnessed outside Westfield yesterday evening," said Chief Superintendent Mark Bird, who was in charge of the policing operation.