Thousands of protesters from civil rights groups walked down New York City's Fifth Avenue in total silence Sunday, marching in defiance of "stop-and-frisk" tactics employed by city police.

The quiet was interrupted only by the tapping of feet on the pavement and birds chirping as protesters strode along Central Park from Harlem to Mayor Michael Bloomberg's town house on the Upper East Side.

For almost 30 city blocks, the march moved slowly and silently. Then, as they moved past Bloomberg's home, the crowd erupted in protest chants. The house on East 79th Street, off Fifth, was blocked by police barricades.

"We've got to fight back, we can't be silent!" a group of activists shouted as the march wound down, with a lineup of buses waiting to take protesters away.

It was not known if Bloomberg was at home when the protesters passed.

Critics say the NYPD's practice of stopping, questioning and searching people who police consider suspicious is illegal and humiliating to thousands of law-abiding blacks and Hispanics. Last year, the NYPD stopped more than 600,000 people, up from more than 90,000 a decade ago.

Later Sunday, tension increased between police officers and a group of protesters who tried to keep walking down Fifth Avenue below East 77th Street.

Police officers on scooters lined both sides of the avenue and officers on foot formed a row to keep people on the sidewalk. Several scuffles broke out between screaming protesters and officers who pushed them behind barricades on the sidewalk.

One woman was seen wrestling with police officers before being arrested. Police officers were seen making a handful of arrests. The exact number of people arrested was not immediately available.

Resting on a bench nearby, Samantha Tailor, a mother of two from the Bronx, said her 16-year-old son came home from school "very upset" last month after he and two friends were stopped on their way to classes that morning. That was the second time for her son in recent months, she said.

"Thank God, he had his ID," Tailor said. "He wasn't doing anything wrong, just walking to school."

And when officers pushed the three against a wall and went through their pockets, "he told me he was very quiet, very humble."

Tailor said she had taught him what to do if he were stopped.

The practice of silent marches dates to 1917, when the NAACP led a protest through New York against lynchings and segregation in the U.S.

"We are black, white, Asian, LGBT, straight, Jewish, Muslim and Christian," New York City Council member Jumaane Williams said before the march began, standing alongside American Federation of Teachers President Randi Weingarten. "Mayor Bloomberg has been our great uniter. We've been screaming loudly, and he hasn't heard us, but hopefully he'll hear the deafening silence."

Last year, the NYPD stopped more than 685,000 people, mostly black and Hispanic young men — up from about 97,000 a decade earlier, according to the New York Civil Liberties Union, which also was to join the march. About half of those stopped are frisked, and about 10 percent are arrested.

"In most cities, when you ask who gets beaten up by the cops, the answer comes back: black people, people of color, and the gay community," Benjamin Jealous, head of the National Association for the Advancement of Colored People, said on MSNBC.

Jealous said that "the notion that this make us safer really defies logic," noting that other large cities have cut their crime rate without resorting to stop-and-frisk methods.

Bloomberg and Police Commissioner Ray Kelly defend the policy, saying the program keeps guns off New York streets and helps stop crime before it happens.

Speaking at a Christian cultural center on Sunday in Brooklyn, Bloomberg said he is working with police to ensure that people are treated respectfully when they are stopped.

"I cannot in good conscience walk away from work that I know will save the lives of so many of our brothers and sisters, and I will not," the mayor said.

Weingarten said it was the first time that members of the LGBT community marched with the black community for the same cause.

"They're being stopped because of the color of their skin, not because of who they are," she said.