Add Category
Videos posted to social media appeared to show a male officer being pinned to the ground and kicked, before a female officer intervenes. A squabble then plays out for around a minute between the two officers and a group of men.
The Metropolitan Police confirmed on Thursday that two men, aged 20 and 38, have been arrested on suspicion of assault on police.
Wednesday's incident has drawn a sharp response from the UK's police association and Home Secretary Priti Patel, who wrote on Twitter that the attack was "sickening, shocking & disgraceful."
Police said in a statement to CNN that the incident began when two officers on patrol were flagged down by a member of the public, who said they had just been assaulted and directed the officers towards their alleged assailants.
A struggle ensued when "one of the men resisted," police said. "A number of other people became involved whilst the officer was on the ground," they added.
The two officers sustained minor injuries and did not require hospital treatment.
"We are not society's punchbags," the Metropolitan Police Federation's chairman Ken Marsh added in a statement. "On this occasion our colleagues are thankfully only reporting minor injuries -- but the reality is it could have been much worse."
London's mayor, Sadiq Khan, said: "Attacks on our police will not be tolerated." He added: "These brave officers were doing their duty and assisting the public -- I wish them a speedy recovery."
Khan has supported the protests, which saw tens of thousands take to the streets in London and other UK cities, but he condemned the small number of demonstrators who were involved in tense scenes with officers.