D.C. Police Chief Maurice T. Turner Jr. urged Washington residents yesterday to stay away from today's scheduled noontime rally and march down Pennsylvania Avenue by a Ku Klux Klan group and the various counter-demonstrations that are planned.

Between 50 and 200 members of the Knights of the Ku Klux Klan, with headquarters in Tuscumbia, Ala., are expected to meet at the Capitol and march to a rally in Lafayette Square across from the White House.

A broad cross-section of area and national groups, ranging from the Council of Churches of Greater Washington and various mainstream labor organizations to Socialist groups and numerous self-proclaimed grass-roots organizations, have scheduled actions protesting the Klan.

At a press conference yesterday at which he announced activation of at least 300 members of the police department's Civil Disturbance Unit to cover the demonstration, Turner said, "It's quite obvious that a group such as the Klan will evoke a great deal of animosity among the citizens of this city.

"I am personally recommending that the people avoid the rally. Any outside attendance would only serve to draw greater attention to it."

Turner's plea came against a backdrop of protests by many residents, some of whom, speaking on local radio and television talk shows, have said they particularly object to the Klan's appearance in a city whose population is 70 percent black.

When asked how he as a black chief of police felt about the Klan's appearance here, Turner replied, "I'm a chief of police, whether black or white. I'm the sworn chief of police for this community and it's my duty to see that the peace is preserved. So therefore I assure you and the community that Saturday will be a peaceful day. It's the federal government that they are protesting against, not the District government."

Turner said he has taken "all steps to try to stem any possible confrontations," and plans to isolate the Klan at all times. Consequently, he said, he expected large traffic tie-ups and urged motorists to avoid the area -- especially during the morning and early afternoon.

"The best intelligence that we have," he said, "is that the number of Klansmen who will show up will be in the lower double digits and there will be far more anti-Klan and news media activity."

A spokesman for the Ku Klux Klan has said the group is coming to Washington primarily to protest an immigration bill that would give amnesty to millions of illegal aliens who arrived here before 1977, but would put new controls on future immigration. The bill has been passed by the Senate and now awaits a vote in the House.

Stanley McCollum, director of the national office of the Knights of the Ku Klux Klan and the organizer of today's planned march, said earlier this week that if the bill passes the legalized aliens would "get on welfare, get food stamps and bankrupt the country."

Don Black, grand wizard of the organization, had planned to lead today's march, but yesterday, he was told by federal authorities in New Orleans that he would be arrested if he came here.

Black was convicted in 1981 of violating the federal Neutrality Act by attempting to overthrow the prime minister of the Caribbean nation of Dominica. He was sentenced to three years in prison and is free on $250,000 bond pending an appeal.

"My attorney said I would be arrested immediately if I went," Black told United Press International. "The U.S. magistrate's office said my bond money would be forfeited if I was arrested," he said.

Thomas Robb of Arkansas, the national chaplain of the organization, is expected to take Black's place at the head of the march.

The Klan members, many said to be coming from the South and the Midwest, are expected to wear their white robes and pointed-top head-pieces tomorrow, but none will wear masks.

D.C. Del. Walter E. Fauntroy, a leader of the Coalition for Community Unity, a counter-Klan umbrella group that is sponsoring several nonviolent and nondirect-action protests to today's scheduled march, yesterday urged those opposed to the Klan to join one of several coalition activities.

The group, composed of labor organizations and churches that Fauntroy helped organize, will serve free dinners at 30 area churches to families of the unemployed, hold worship services at the city's prisons and a noontime ecumenical service at the National City Christian Church on Thomas Circle NW, and sponsor a job counseling service at the same church.

"There are alternatives to standing around watching the Klan which can be much more meaningful," said Fauntroy.

A group calling itself the Labor/Black Coalition to Stop the Klan in Washington, D.C. also held a press conference yesterday and predicted that about 5,000 people would meet at the foot of the Capitol where the Klansmen are scheduled to begin their march, but would not cross police lines.

"If the Ku Klux Klan shows up, they will find thousands of us standing up right there," said Don Andrews, of the Spartacist League, a New York-based Socialist organization that is a cosponsor of the rally.

The November 29th Coalition, a year-old American group organized to support the Palestinians, said they would also join anti-Klan demonstrations with a march from the Ellipse to McPherson Square.

Demonstrating at McPherson Square, beginning at 9 a.m., will be the All People's Congress. The group has a permit to march from the square to Ninth and E streets NW and return to the square. The group's parade route will be separated by a block from the Klan's route along Pennsylvania Avenue NW.

The National Anti-Klan Network has scheduled a demonstration on Pennsylvania Avenue, and Nicholas F. Boke, a high school teacher, has scheduled another anti-Klan protest on the steps of the Lincoln Memorial at noon.

On Nov. 6, a handful of Klan members rallied in a remote Montgomery County park, sparking a large counter-rally downtown, but there were no serious incidents.