A senior police chief has spoken out after warnings that violent suspects could go free if officers are not backed up by members of the public.
Metropolitan Police Assistant Commissioner Sir Steve House said passers-by should only help officers struggling with violent suspects "if they can safely do so".
A debate was sparked after video footage of two officers being attacked as they tried to make an arrest in south London was shared hundreds of times online.
One was dragged around in the road while the other took a flying kick to the chest and was left lying dazed feet from a passing bus.
The footage was posted on Twitter with the caption "south London at night...Lol", and showed several cars going past without stopping.
One member of the public, wearing a crash helmet, did intervene and helped the officers arrest one of the suspects.
In a statement on Tuesday, Sir Steve said: "Whilst officers should never expect to be attacked as part of their job, a core part of officer safety training is ensuring they know how to respond to volatile situations.
"This training is substantial and delivered in accordance with national guidelines and we regularly review it to make sure it is fit for purpose. Officers are also issued with personal protective equipment to help protect them and the public.
"I am mindful that members of the public do not have access to such items and, while any officer would be grateful for the public to assist them with a difficult arrest, they should only intervene if they can safely do so."
He said suspects trying to flee arrest was "not a new phenomenon" and that officers in London know there is "overwhelming support for the work we do from the public".
‘Risk-assess it dynamically’
In the wake of the attack, chairman of the Metropolitan Police Federation Ken Marsh warned that officers might be forced to let violent suspects go.
He said: "Are we now in a society where, if we think we can't detain somebody, we just let them go? It's just not worth it.
"We're going to come to a point where we're going to start pushing messages out to our colleagues: 'Risk-assess it dynamically and, if you think you can't detain a person, just let them go.'
Talking to Mike Graham on talkRADIO, Chris Hobbs a former Metropolitan police officer has said that the police “need more support.”
“The very least you can do to intervene is per say phone calls, look at the old grannies who wade in and assist the police,” he said.
“What Ken Marsh is saying in actual fact is that on the streets the police need more support.
“What you’re getting in some of these areas, especially at night, is you’ve got collections of yobs: it’s the yobs who are filming, it’s the yobs who are jeering, it’s the yobs that are not assisting and that is something really is untenable.”