Police bolstered by emergency orders maintained close watch Tuesday over protest-wracked streets in Ferguson after another night of demonstrations saw multiple arrests and brought new potential flash points.

Authorities said Tuesday that there was no repeat of the violence seen a night earlier, when gunshots erupted on the streets of this small suburb of St. Louis.

The St. Louis County Police Department said 22 people were arrested on Monday night and into Tuesday morning during demonstrations in the city. Another 63 people had been arrested while stopping traffic during the Monday evening rush hour, officials said. Most of these people were charged with interfering with police officers.

The latest wave of unrest — set in motion after violence erupted during marches marking the anniversary of the shooting of an unarmed black man — has reopened the deep racial tensions in Ferguson and brought scenes reminiscent of the riots that gripped the St. Louis suburb last year after the death of Michael Brown.

Protesters chanted to the beat of drums in marches along West Florissant Avenue — the epicenter of last year’s clashes — in a show of solidarity that spilled into early Tuesday. Some demonstrators pelted riot police with frozen water bottles and stones.

In a sign that the confrontations could be easing, police on Monday night and early Tuesday morning did not respond with tear gas, and no looting or injuries were reported, said St. Louis County police spokesman Shawn McGuire.

But there also were hints of possible escalations.

Demonstrations spilled into downtown St. Louis as about 60 protesters, including civil rights activist Cornel West, blocked the entrance to the federal courthouse on Monday. Later, another group briefly halted traffic on busy Interstate 70 during the evening rush hour Monday, leading to dozens of arrests there.

In Ferguson, meanwhile, multiple heavily armed white men staged a vigilante-style show of force, claiming they were protecting someone working for a self-proclaimed conspiracy-hunting Web site, infowars.com, which has included reports on the unrest.

The armed men identified themselves as part of a group called “Oath Keepers,” which describes itself as an independent coalition that protects civil rights. The group, which has made appearances at previous upheavals in Ferguson over the past year, has been denounced by local law enforcement.

“Their presence was both unnecessary and inflammatory,” said St. Louis County Police Chief Jon Belmar.

The group says on its site that its members are focused on defending the Constitution, but the Southern Poverty Law Center has described the “Oath Keepers” as a “fiercely anti-government, militaristic group.”

Early Tuesday morning, as protests were winding down, members of the group arrived on West Florissant Avenue. Clad in military-style camoflauge and bulletproof vests, they were toting long guns and insisted to protesters they were “on their side” and there to protect the demonstrators.

Protest leader Talal Ahmad, 30, called it a provocation.

“You’re going to bring some uncommissioned citizens, white citizens, into a black community like this? It’s disrespectful,” Ahmad told the Reuters news agency.

A day earlier, the largely peaceful protests that began Sunday morning with a silent march had been overtaken by nightfall with what appeared to be random violence and opportunistic looting.

An 18-year-old black man shot by police, Tyrone Harris Jr., had been with two friends who were trying to sell a stolen flat-screen television, according to his girlfriend and relatives.

Harris remained in critical condition. Police charged him with 10 counts of assaulting law enforcement, shooting at a motor vehicle and armed criminal action.

The shooting — along with a state of emergency declaration on Monday — served to push tensions higher.

“The recent acts of violence will not be tolerated in a community that has worked so tirelessly over the last year to rebuild and become stronger,” St. Louis County Executive Steve Stenger said in a statement declaring a state of emergency. “The time and investment in Ferguson and Dellwood will not be destroyed by a few that wish to violate the rights of others.”

The order empowered the county police force to oversee operations in Ferguson and surrounding areas, effectively placing the Ferguson police in a supporting role.

A Justice Department report in June sharply criticized the “military-style” tactics used by Ferguson officers seeking to quell the riots after the Brown shooting last year, including deploying armored vehicles and snipers. Justice investigators also opened a review of policies by St. Louis County police, including possible racial profiling of suspects.

Police units from the St. Louis area arrived in Ferguson on Monday — a day after protest crowds swelled in the wake of the shooting of Harris.

Police said the shooting began after looters broke into storefronts. Meanwhile, plainclothes detectives farther down the avenue were monitoring two rival groups of young men, including Harris, whom they believed to be armed.

The groups exchanged between 40 and 50 shots in about 45 seconds, “a remarkable amount of gunfire,” said the county police chief Belmar.

Belmar said Harris then broke away from the rival groups. As an unmarked police SUV with flashing interior lights zoomed toward him, police said, Harris began firing at the vehicle, striking the hood and windshield multiple times.

The detectives returned fire. Harris was later found to be armed with a 9mm Sig Sauer pistol that had been reported stolen last year, Belmar said.

“They were criminals,” Belmar said of the two groups shooting. “They weren’t protesters.”

Harris was shot in the arm, legs, back, chest, liver and groin and taken to Barnes-Jewish Hospital, said his father, Tyrone Harris Sr., adding that his family has been denied entry. Relatives said they do not believe Harris was armed, though they acknowledged that he faced felony charges last year that involved a high-speed chase in a stolen vehicle.

The four detectives involved in the shooting were placed on administrative leave; they have not been identified. None were wearing body cameras — equipment activists have demanded in the past year.

Harris’s father, however, said he has deep doubts about the police account of the shooting. “There ain’t no child perfect. And I don’t claim he’s a perfect person,” he said. “He had gotten in trouble with law and made some mistakes, but he was trying to get his life together.”

Also on Monday, a reporter for the St. Louis Post-Dispatch who was beaten and robbed covering the protests on Sunday night was released from the hospital, according to that newspaper.

Berman and Wan reported from Washington. Wesley Lowery in Ferguson and Sarah Larimer, Julie Tate, Jennifer Jenkins, Alice Crites, J. Freedom du Lac, Justin Wm. Moyer, Abigail Ohlheiser, Nick Kirkpatrick and Brian Murphy in Washington contributed to this report.