Phoenix Crowd Hosed With Pepper-Spray by Federal Agent in Drive-By, on Video

Following weeks of protest in Minnesota, residents of Phoenix, Arizona are now responding to federal agents descending on their city … and fresh video shows a crowd blasted by pepper-spray in a drive-by attack by DHS officers.

In new video, protesters gather at a sidewalk to yell at two trucks driving past ... and get hosed in their faces by pepper-spray without real provocation. Watch the clip ... people hold signs and chant in the parking lot of Zipps Sports Grill in north Phoenix when two unmarked pickup trucks pull up.

The video shows the passenger-side window of the second truck open, and a torrent of pepper-spray is fired at the group standing on the sidewalk. The men inside -- later identified by a local news outlet as HSI officers -- drive off as one pedestrian is brought to their knees by the chemicals.

KPHO-TV reports the men were Homeland Security Investigations officers ... and notes no violence was reported at the scene. And the video shows nothing to reasonably suggest the officers were under any threat at the time.

Dr. Roy Taylor, an expert in police procedures, told the outlet ... "Based on what we could see, there was no justification for any use of force."

Taylor continued ... "I think the officers fell victim to mob mentality, thinking they were anonymous -- 'Nobody knows who we are, we are wearing masks, don’t have logos on uniforms, our vehicles are unmarked' -- and they thought they could probably get away with a little street justice by squirting some of the agitators as they drove away."

The incident reportedly followed a raid on the same restaurant Monday. The Arizona Republic newspaper reports DHS personnel were involved in several other pepper-spray incidents across the city Tuesday night.