A police offer was punched in the face as a man was being arrested in Southall on suspicion of possessing a firearm on Sunday night (May 28).
Officers had responded at around 8.10pm to a report of a firearm being seen in a car being driven through Ealing.
The vehicle was followed to Hayes Bridge Retail Park, where a large number of people were already gathered for what police described as "an unofficial 'car rally' event".
Local residents reported seeing as many as 20 police cars, armed officers and the police helicopter in attendance.
Police blocked off Uxbridge Road/The Broadway between Springfield Road and South Road, causing heavy traffic in the area during the evening.
Residents in Southall also said they heard loud revving sounds coming from the retail park and up and down The Broadway until late on Sunday.
The man arrested on suspicion of possession of a firearm was taken into custody at a west London police station. Police said no firearm had been recovered.
Police made six further arrests for public order offences and other offences including possession of drugs and assault on police.
A second police officer suffered a broken finger during the incident.
The organiser and founder of the monthly 'West London Meet' cars gathering said he had been told by police that "the reason for it [the event] being shut down was not because of the meet, but due to the police looking for someone in the vicinity, and as the crowd grew more aggravated the police called for back-up".
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