Forty-four Ku Klux Klan members preached to themselves yesterday on the steps of the U.S. Capitol after more than 3,000 anti-Klan demonstrators prevented them from marching down Constitution Avenue from 15th Street NW.

More than 2,000 police officers -- spread out over 16 blocks of the Mall, Constitution Avenue and the Capitol grounds -- succeeded in keeping Klan members and their opponents away from each other. There was some rock-throwing and fighting, and a lot of yelling at police.

District, U.S. Park and Capitol police were equipped with riot gear, tear gas, helicopters, horses and dogs, hoping to prevent a recurrence of the rioting that accompanied the Klan's November 1982 visit to the nation's capital. The massive police presence yesterday snarled traffic for blocks, angered some bystanders and confounded tourists who had come to enjoy a rare low-humidity late summer day downtown.

"There aren't this many cops in the whole state of Nebraska," said Marvin Dybdahl, of North Platte, Neb.

Police, the Klan and the anti-Klan demonstrators all claimed some measure of victory. D.C. Police Chief Isaac Fulwood Jr. said a key decision for public safety was made when police, realizing how large the anti-Klan crowd was at 15th and Constitution, decided to escort the Klansmen directly to the Capitol from the Pentagon parking lot, where they had met the police.

Virgil Griffin, of North Carolina, leader of the Christian Knights of the Ku Klux Klan, the Klan faction that held the rally, said he agreed to the request "for the safety of police. If we had walked, it would have got some police killed."

And Craig Newman, spokesman for the All Peoples Congress, a national group that organized the anti-Klan activities in 1982 and this year, called the Klan's decision not to march "a complete victory for us. They did not show at 15th and Constitution and they did not march."

The Christian Knights are one of 40 Klan factions in the country. The last time a Klan group rallied in Washington, on Nov. 29, 1982, hundreds of protesters went on a rampage for two hours after Klan members were driven by police to Lafayette Square and left before the activists could get there.

Those anti-Klan activists broke store windows around Lafayette and McPherson squares, looted small businesses and fought with D.C. police.

Yesterday's incident resulted in three arrests and eight injuries, according to police. Four of those injured were police officers. Police said one of those arrested was a 17-year-old who was apprehended after inciting a group of black youths to beat up an older, short-haired white man by yelling, "Get the skinhead."

For most of the afternoon, a row of police and two rows of police cars lined the north and south sides of Constitution. Police alternately held people back and let them move into the street.

"The police need to be congratulated for maintaining their cool," said Rick Sowell, a D.C. youth worker assigned to work the crowd this year, as he had in 1982. "Some of the kids don't understand {the police} are only doing their job. When {the kids} tried to shake a police car and then climbed up on it, the police allowed them to do it. They accepted it even when you could tell they didn't like it."

Some black demonstrators taunted black police officers for protecting a white supremacist group.

D.C. Police Officer Synthia K. Brown was one of those being taunted. She stood at 14th and Constitution, nightstick in hand, gas mask at her side, defending herself against criticism from fellow blacks.

"Me, as a police officer, I had no choice in the matter whatsoever," she told a young woman, one of three people standing near her.

"You were black before you were a police officer," the woman said to her.

Brown -- at times smiling, at times frowning -- was firm. "I'll be black tomorrow. I'll be black this afternoon. I'll be black forever," she said. "You know what you're preaching? Reverse racism."

The anti-Klan crowd was about two-thirds black and included gay-rights activists, union activists and hundreds of unaffiliated people.

The voices over megaphones came from two largely white groups of the radical left: the All Peoples Congress and the International Committee Against Racism.

The former is an affiliate of the Workers World Party, according to Mira Boland, of the Anti-Defamation League, which monitors the Klan and anti-Klan groups. The latter is connected with the Progressive Labor Party, which has a history of attacking police, Boland said.

A few voices urging nonviolence could be heard in the crowd.

Positive Force, a group of white and black teenagers and college students from suburban Maryland and Virginia, played drums and chanted anti-violence statements. Priests and seminarians from the Oblates of Mary Immaculate stood well away from the crowd, praying.

Maurice Halder, 23, of Oxon Hill, said he came "to let the Klan know . . . that not everybody thinks like them."

Effi Barry, wife of D.C. Mayor Marion Barry, had brought her son, Christopher, and one of his friends because, she said, both boys were frightened when they heard the Klan was coming to town. "I'm overwhelmed that in the year 1990 we still have to deal with this problem," she said.

In fact, few people heard the Klan's racial slurs and comments about American communists because police had closed off the east side of the Capitol to everyone except the Klan and the media.

Police allowed the demonstrators as far east as Constitution and Louisiana avenues NW, next to the Labor Department. For the next two hours, the crowd milled around, waiting for the Klan members they wouldn't see.

As 4 p.m. approached, police made their first announcement to the crowd: They were reopening all but a small stretch of Constitution to normal traffic.

"We wanted to exchange some political blues with the Klan," complained Al Campbell, a 26-year-old from Hyattsville. "The police are hiding them."

Staff writers Stephen Buckley, Ruben Castaneda, Bill Dedman, Gabriel Escobar, Stephen C. Fehr, Eric Charles May and Carlos Sanchez contributed to this report.