Two more men have been arrested after a teenager was stabbed and two men injured following a crash involving two cars.
The crash happened in Clifton Street, Swindon, at 19:45 GMT on Saturday.
A 24-year-old man from Swindon has been arrested on suspicion of grievous bodily harm with intent and possession with intent to supply Class A drugs.
Another 24-year-old man, also from Swindon, has been arrested on suspicion of grievous bodily harm with intent.
They both remain in custody.
Police said a large quantity of drugs was also seized from an address in the town centre.
Det Insp Paul Hacker, from Swindon CID, said: "This is a complex investigation involving a large number of people involved in a disorder, as well as a number of witnesses who are continuing to help us piece together exactly what happened on Saturday night.
"Please don't be alarmed if you continue to see a police presence in some parts of Swindon, we will be carrying out extra patrols to provide some reassurance for the community."
A 20-year-old man arrested on Saturday night has been released under investigation while inquiries continue.