A 12-year-old boy is among three people arrested on suspicion of possession of a firearm after an incident in Newbury.
A fourth man was also arrested on suspicion of possessing an imitation firearm.
Officers have said there is no risk to the wider public.
The arrests followed an assault on The Oaks, Newbury, at around 6.14pm on Tuesday (May 28).
The victim, a teenage boy, did not sustain any injuries.
Thames Valley Police is now appealing for any witnesses to come forward.
They also made four arrests on Tuesday.
A 12-year-old boy from Newbury was arrested on suspicion of possession of a firearm with intent to cause fear of violence and possession of a bladed article in a public place.
A 17-year-old boy from Newbury was arrested on suspicion of possession of a firearm with intent to cause fear of violence.
An 18-year-old man from Newbury was arrested on suspicion of possession of a firearm with intent to cause fear of violence.
And a 20-year-old man from Newbury was arrested on suspicion of possession of a bladed article in a public place, possession of an imitation firearm with intent to cause fear of violence, and using threatening/abusive/insulting words/behaviour to cause harassment/alarm/distress.
They have all been released on police bail until August 8.
Investigating officer DC Izzy Dennis, based at Newbury police station, said: “The investigation is ongoing at this time but I would want to reassure the public that we are not seeking anyone else in connection with this incident and that there is no risk to the wider public.
“I would like to appeal to any members of the public who have witnessed this incident and ask them to contact the police in order to discuss what you have witnessed and for any members of the public who may have been passing through the area at the time to check any dashcam or similar footage.”
You can make a report by calling 101 or online, quoting reference 43240249323.
Alternatively, you can anonymously contact the independent charity Crimestoppers on 0800 555 111 or its website.
