A police officer was injured while attempting to break up a street party of around 200 people celebrating Eid.
Officers were called shortly before midnight on Thursday to Ilford in east London.
Officers approached the crowd and asked them to go home, but as some people dispersed a fight broke out.
Police rushed to break up the fight between the two groups and one officer suffered a head injury in the commotion.
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One man was arrested on suspicion of a public order offence and assaulting an emergency worker.
Chief Superintendent Stephen Clayman, of the Met’s east area command, said last night he was ‘concerned’ about the size of the gathering during the coronavirus crisis.
‘While we accept that celebrations take place, and we have no desire to spoil them for the community, if they descend into violence we absolutely will step in,’ he added.
‘A number of calls were received last night from concerned members of the public and while we appreciate this is a time of excitement and celebration for some, the sight and sound of such a large group was concerning and even distressing for others.
‘That this size of gathering has taken place during a pandemic is concerning. I remind all of our communities to respect each other and ensure that the Government guidelines around social distancing are followed.
‘Following a work day of protecting the public, one of my officers has had to return home to his family with a head injury.
‘This is beyond unacceptable and I would like to be very clear that anyone assaulting an officer in the course of his or her duty will be arrested and placed before the courts.’
Scotland Yard confirmed the Met’s Directorate of Professional Standards has been notified and will review body worn cameras.
It comes after scientific advisers warned serious public disorder could ‘overwhelm all attempts’ to control the pandemic, in the light of a number of unlicensed music events and large-scale protests taking place in recent weeks.
Eid is traditionally marked by large crowds gathering in prayer and sharing food, but people have been forced to keep their distance and wear face masks this year due to the coronavirus pandemic.
Huge numbers of Muslims across the world have been pictured celebrating Eid-al-Adha at a distance, with measures in place to keep worshippers safe.
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