A crowd gathered at City Hall, kneeling for more than eight minutes in honor of Floyd, a black man who died after a white officer pressed a knee into his neck.
The protesters then marched through Center City to the Philadelphia Museum of Art on Saturday at about noon.
THE LATEST: Looting continues amid clean-up efforts in Center City Philadelphia Sunday.
But by 3 p.m., things turned violent.
Chopper 6 was over the scene as demonstrators marched down Ben Franklin Parkway, letting their voices be heard: "Never stay silent! Never stay silent!"
Outside the Municipal Services Building, protesters sprayed graffiti on a statue of former Philadelphia Mayor Frank Rizzo, tried to topple it and set a fire at its base.
Chopper 6 showed the group clashing with police officers. Several cars were set on fire and later, the Starbucks coffee kiosk in Dilworth Park was set ablaze.
Crowds of people were soon seen looting multiple businesses in Center City.
Chopper 6 showed a group of people looting a North Face store in the 1500 block of Walnut Street.
They smashed the window, then climbed in. Multiple people were seen leaving the store with merchandise.
By 9:30 p.m., a massive fire broke out in a three-story building near 17th and Walnut streets.
Flames could be seen shooting from the roof as police guarded firefighters who worked to battle the blaze.
Police Commissioner Danielle Outlaw said at least 13 police officers were injured at several locations throughout the city.
She said the officers were injured while attempting to control crowds, make arrests, prevent acts of vandalism, and also as the result of liquid and solid projectiles being hurled at them.
There were also injuries to civilians, she said, but specific numbers have not yet been released.
"The actions of those persons were unlawful, and were not in furtherance of any noble, or ethical issue or cause," she said.
Outlaw said four police vehicles were set on fire, including one state police vehicle.
Mayor Jim Kenney said that while citizens are justified in their anger, none of the acts of violence or damage to property will do anything to restore faith and trust between police and communities of color.
"We will get through this. We will continue to hold bad cops accountable, and will hold those who did these acts today, accountable also," he said.
At least 14 people have been arrested in connection with the violence, Outlaw said.
A mandatory citywide curfew was put into effect through 6 a.m. Sunday. The curfew will also be in place on Sunday night and into Monday morning. Only essential duties will be allowed outdoors.
I signed an executive order implementing a curfew in Philadelphia for 8 p.m.–6 a.m. tonight and tomorrow night. During this time, people may leave their homes only to go to work at essential businesses or to seek medical attention or police assistance. https://t.co/pRvEtTW1da pic.twitter.com/zebPusHWCR— Jim #StayHomePHL Kenney (@PhillyMayor) May 31, 2020
Outlaw said officers were actively enforcing that order.
The fire was placed under control just after 1 a.m.
Firefighters remained on scene Sunday morning, dousing hot spots.
The Associated Press contributed to this report