I watched some live streams of the event. There were more than a few antifa, there were hundreds in fact. They were assaulting the Patriot prayer group, scuffling with police, beating up trash cans and smashing windows, the usual stuff. I don’t know why Fox news is not identifying them as antifa in this article.
“Refuse Fascism and By Any Means Necessary were the two largest and most vocal groups on the far-left...”
https://www.berkeleyside.com/2018/08/05/protests-sweep-through-downtown-berkeley-again
Authorities said nearly two dozen city vehicles were also vandalized with their windshields broken and one was set on fire by an incendiary device....Police said they were surprised by the lack of injuries “given that extremists threw explosives at Berkeley Police and Alameda County Sheriff’s Office mutual aid officers.”
https://sanfrancisco.cbslocal.com/2018/08/05/berkeley-rally-arrests/