Phoenix Police Use Pepper Spray, Tear Gas as Black Lives Protest Turns Chaotic

Phoenix police clashed with Black Lives Matter protesters on Friday night after cops say rocks were thrown at them and the assembly had become "unlawful."

A protest erupted into chaos on Friday as Arizona police pepper sprayed protesters and even resorted to using tear gas.

Around 1,000 demonstrators took to the streets of Phoenix on Friday in the wake of the recent police-involved killings of black men in Louisiana and Minnesota.

Tear gas deployed at 7th St and McKinney. Crowed dispersing. Avoid the area pic.twitter.com/Ye1LFugerd

— Damon Cecil, PIO (@dps_pio_cecil) July 9, 2016

The march remained peaceful for hours, but Phoenix PD chose to label it an "unlawful assembly" just before 11 p.m. as marchers changed course in order to shut down an area freeway.

Read: Suspect in Dallas Shooting That Left 5 Officers Dead 'Wanted to Kill White People, Especially White Cops'

Officers lined up shoulder to shoulder in an attempt to block a march toward Interstate 10. 

Protestors throwing rocks at Phoenix PD. #Phoenixrally. Suspect in custody. Please avoid the area. pic.twitter.com/HykybQvDmj

— Damon Cecil, PIO (@dps_pio_cecil) July 9, 2016

"Certain sections of the street were blocked off to allow them to peacefully gather and demonstrate in the way that they had intended," Sgt. Vince Lewis said at an early morning press conference. "Once actions had changed, those officers then formed lines to not only protect the surrounding community but [also create] a presence to help enforce laws and maintain peace. Once the officer felt some of the demonstrators got too close to their lines, the pepper balls were deployed to move those people back."

A group of protesters with their hands in the air lined up opposite the police, many of them chanting "Hands up, don't shoot."

Read: Pictured: Newlywed Transit Officer and Military Veteran Among 5 Dallas Sniper Victims

Video footage from the demonstration appears to show riot gear-clad police using tear gas and pepper spray as protesters quickly backed away.

7th St / Roosevelt: Police have now declared this an unlawful assembly. pic.twitter.com/1LPhpBRfFL

— Jon Erickson (@JonEricksonTV) July 9, 2016

Police said three people were arrested at the scene after allegedly throwing objects at officers, KPHO reports.

"All in all, with the number of people that were there and only three arrests, it's leaning towards a successful event," Lewis said.

The protests came one day after outrage over the deaths of Philando Castile and Alton Sterling spurred protests nationwide, including in Dallas, where 25-year-old Army reservist  Micah Xavier Johnson ambushed and killed five police officers on Thursday at a rally.

Watch: Hero Mom Wounded While Shielding Her Sons From Gunfire During Dallas Sniper Attack