SWAT teams, local police officers and private security were deployed all throughout Bev Hills Saturday in anticipation of major unrest over the next few days. City officials had already announced they'd be doing this -- along with shutting down ritzy Rodeo Drive -- but it appears they wanted to get the muscle out well ahead of time to set a tone.

Check out these shots we got of armored trucks lining the streets, with officers in full tactical gear ... ready to rock and roll if s*** hits the fan. Not only that, but several different shops, storefronts and boutiques along Rodeo were doing a full board-up blitz as well.

Might've been a good move to get the ball rolling on this, because as it turns out ... there are dueling protests happening nearby right now, and violence appears to already be breaking out between anti-fascists and Trump supporters. The former were seen marching toward the latter near the famous Beverly Hills Sign in Beverly Gardens Park. Apparently, these clashing demonstrations have become a regular thing around there, especially lately.

We've got eyes on the ground ... and we're told cops are already breaking up some of the fights, which is leading to more aggressive behavior and violence by default. One of our brave photogs, Melanie, even got shoved to the ground by a cop -- which you see in our clip -- this just seconds after they declared the protests unlawful assemblies and started dispersing the crowds.