(CNN) -- Protesters angry over the acquittal of ex-police officer Jason Stockley, a white cop on trial for murder in the shooting death of a black man, were back in the streets of downtown St. Louis early Monday after demonstrations the previous night turned violent.
More than 80 people were arrested late Sunday as protesters attacked police, broke windows and flipped over trash cans, authorities said.
On Monday, protesters were locking arms on Market Street, a few blocks from the site of the previous night's violence.
"Protesters were mostly silent," said Bryan McClellan, who participated in the demonstration. "We want to achieve one goal -- an end to the disparate killings of black citizens at the hands of police."
It was the fourth day of protests, which began Friday after Stockley was acquitted in the killing of 24-year-old Anthony Lamar Smith. Though the Stockley incident happened almost three years before Officer Darren Wilson killed Michael Brown in nearby Ferguson, Missouri, the unrest in Ferguson renewed interest in the case.
Photos: The weekend in St. Louis
Sunday night's demonstrations began peacefully, but erupted in violence after nightfall, officials said. Amid the melees that ensued, some protesters broke concrete flower pots and used the broken pieces as projectiles.
"Some criminals assaulted law enforcement officers and threw chemicals and rocks at them. All of the officers' injuries were minor or moderate. All will be returned to duty soon," acting Police Commissioner Larry O'Toole said. "We're in control. This is our city, and we're going to protect it."
According to multiple reports, including that of St. Louis Post-Dispatch photographer Dave Carson, officers chanted, "Whose streets? Our streets!" after making arrests Sunday night along Tucker Boulevard. The Post-Dispatch is a CNN affiliate.
'This is not acceptable'
The St. Louis Metropolitan Police Department's Twitter feed reported several incidents Sunday night of protesters failing to disperse along downtown's Tucker Boulevard and Olive Street. The department also shared images of damage to an eye-care shop, a personnel services office and a Japanese restaurant.
The St. Louis County Police Department tweeted a photo of a fireman "decontaminating our officers" after "unknown chemicals (were) thrown on them downtown."
Another police tweet showed a collection of protective gear and weapons, including a handgun, that authorities say were confiscated from a "rioter."
Carson tweeted that among the arrestees was Post-Dispatch journalist Mike Faulk. Carson called it a "mass arrest" and said people complained they were given no way to exit. Faulk's last tweet of the night said, "Less than 100 of us including media blocked in at wa and Tucker all four sides. People moving toward bike cops looks like best option."
The St. Louis Metropolitan Police Department did not immediately return calls inquiring about the nature of the arrests.
Sunday's vandalism unfolded in a "concentrated area," O'Toole said. Police arrested demonstrators after the violence, which included assaults and chemical attacks on officers, police said.
St. Louis Mayor Lyda Krewson said the majority of protesters were not violent and blamed the vandalism on agitators.