Thousands of demonstrators have rallied outside a Dallas primary school in protest over a white police officer's actions against a mostly black group of teenagers at a pool party.
Some who gathered in the Dallas suburb of McKinney held signs that included the phrases "My skin colour is not a crime" and "Don't tread on our kids".
A few dozen addressed the crowd through a megaphone, including Derrick Golden, a pastor from McKinney who had earlier met the city's police chief Greg Conley.
He said Mr Conley "responded appropriately" after an officer was seen in a video pushing a 15-year-old girl to the ground and pointing his gun at other teenagers.
The officer involved, David Eric Casebolt, is on administrative leave, but Mr Golden said he should be sacked because of the profanities he used and the fact that he brandished his gun.
The demonstrators marched a mile from the school to the Craig Ranch North Community Pool where Friday's incident occurred.
About a dozen counter-protesters held signs supporting police.
As the latest in a series of racially charged incidents hit the US headlines, it emerged that McKinney has been the target of lawsuits accusing the Dallas suburb and its housing authority of racially segregating public housing.
One long-running lawsuit filed in 2008 accused McKinney Housing Authority of restricting federally subsidised public housing for low-income families to older neighbourhoods east of the US 75 highway. The lawsuit pointed out that in the Dallas area, 85% of those receiving so-called Section 8 housing vouchers are African-Americans.
The 2000 census found McKinney's east side was where 68% of the city's black population lived, while neighbourhoods west of US 75 were 86% white.
In 2007, 2,057 of the 2,485 housing units run by landlords willing to accept federal rent subsidy vouchers were on the east side.
The lawsuit was settled with a consent decree in 2012 that aimed to open up the west side to subsidised housing.
As police broke up the crowd, the 41-year-old officer pulled the bikini-clad girl to the ground, then used his knees to pin her down. He also pointed his gun at other teenagers and cursed.
The girl claimed the officer told her to walk away but forced her down after "he thought we were saying rude stuff to him", according to an interview she gave to television station KDFW.
"He grabbed me, twisted my arm on my back and shoved me in the grass and started pulling the back of my braids," Dajerria Becton, 15, told the station. "I was telling him to get off me because my back was hurting bad."
"I understand how he was feeling, everybody surrounding him," she said. "I don't think he should have pulled a gun out on 15-year-old kids."
Jahi Adisa Bakari, the father of a teenage girl at the party, said he would press for the officer to be fired, saying he "was out of control".
But Benet Embry, a black radio personality who witnessed the incident, said it was "not another Ferguson" or "another Baltimore", referring to other police encounters that have left suspects dead and fuelled a nationwide "Black Lives Matter" movement.
"This was a teenage party that got out of hand," Embry said.
Police said the youths did not live in the area and did not have permission to be at the pool in McKinney, an affluent, predominantly white city.
According to neighbours, Embry said, a woman who lives in the community reserved the pool for a party. The homeowners' association limits the number of guests each homeowner may have at the pool to two. But about 130 people, mostly teenagers, showed up for the party, he said.
At one point, several youngsters began jumping over the fence to get into the pool area and were causing a disturbance, Embry said, and a couple of fights broke out.
While he did not agree with the officer's profanity or belligerence, Embry said, police were right to respond.
"That's what they are supposed to do - protect us," he said. "I don't know any other way he could have taken her down or established order."
The police department said the video "raised concerns that are being investigated".
Officer Casebolt joined the police force in August 2005.
Before that, he served almost two years as a state trooper, according to records from the Texas Commission on Law Enforcement.
He took eight hours of cultural diversity training at Collin County Community College in February 2009. He has also taken courses in racial profiling and use of force.
Brandon Brooks, the teenager who recorded the video, told KDFW that tensions rose after a white woman and a black teenager at the party had an altercation. He said the white woman told the teenager "to go back to Section 8 housing".
Brandon said the officer was "out of line" and that he felt compelled to keep filming when Casebolt pulled out his gun.
"At that point, my heart did drop and I was scared that someone was going to get shot and possibly killed," he said.
McKinney mayor Brian Loughmiller said city officials plan to meet community leaders to discuss the incident.
"We really need to come together as a community," the mayor said.
Most people were released, except for one man arrested for interference with the duties of a police officer and evading arrest, police said.