Another day, another rogue music video shoot that ends in the police making an appearance! And this time, the RIOT police!

We seriously thought the LAPD must have been in on this -- hired to be cast members in Tyga's upcoming music video, but NO! THIS is where your tax dollars are going, people of LA!

The Jenner-loving rapper hit Melrose Avenue in West Hollywood today -- apparently without a film permit -- jumped on a rooftop, had his homie waving a flag and had his crew start rolling on the whole thing. Next thing you know, a crowd forms, the cops are called and by nightfall, police in full riot gear show up with rubber pellet guns and all!

That was enough to scare everyone away, including Tyga.

After yesterday's antics in South Central LA, which found Tyga in handcuffs and his bodyguard arrested for an unregistered gun, Blac Chyna's baby daddy hadn't had his fill of trouble, it seems. And what's with his film crew not pulling permits?! We're in Hollywood, y'all! Get with it!