An assertive membership drive by the Ku Klux Klan, long dormant in Canada, is increasing fears that this country's relatively good race relations are being eroded by a growing black-white enmity that some think could lead to widespread racial violence.

Within the next few weeks, Canadian members of the American-based white supremacy group plan to open the Klan's first Canadian office in Toronto, the country's largest city and scene in recent years of increasing clashes among members of different races.

This will be the first step in an intended Canadian recruiting drive by the Klan, which reportedly has made large membership gains in the United States since the late 1970s.

The Toronto office will open in the face of vigorous protests from civic leaders, who see the Klan as a direct challenge to this country's image of tolerance toward the many ethnic minorities among Canada's 23 million population.

News of the Klan's intentions has jolted Canadians already worried that a large influx of nonwhite immigrants since the 1960s has produced a backlash among the predominantly white population.

A Klan spokesman in Toronto said the organization had more than 100 inquiries from people wanting to join since it became known earlier this summer that recruits were being sought.

"The reason for the increased interest is that Toronto is becoming more cosmopolitan, and the races do not mix well together and should be segregated as much as possible," the spokesman said in a telephone interview.

The group opposes nonwhite immigration into Canada, and wants the government to pay nonwhites to return to their countries of origin. As support for this policy, Klan members cite the troubles they say have occurred in the United States because of the mixing of races.

"Look what's happened there -- in Detroit, New York City and Washington -- the looting and rioting," the spokesman said.

The Klan refuses to divulge membership figures, but it is believed to number about 500 in Canada. Besides Ontario, it is active in the West Coast province of British Columbia, and membership drives are planned for Montreal, Ottawa and other Canadian cities.

To avoid the stigma that accompanies the Klan name, which most Canadians associate with a style of American violence alien to themselves, the group has considered starting an auxiliary called the National Association for the Advancement of White People.

The Klan spokesman said their chief Toronto organizer was in Louisiana last week discussing the Canadian expansion drive with David Duke, imperial grand wizard of the U.S. Klan.

Canadians have reacted to the group's emergence in Toronto with dismay and anger. The Klan being in Toronto "is the saddest day in the history of race relations in the city," an official of the Ontario provincial government said.

A Toronto civic leader said he would do everything possible to run the white supremacists out of town.

"I want to slam the door of Toronto in their face," he said.

The Klan had many chapters in Canada during its North American heyday in the 1920s, but has been largely unheard of since. Its reemergence now is one of many developments forcing Canadians to reexamine the long-held belief that their racial practices are superior to those of their American neighbors.

In recent years, nonwhites across the country have challenged the myth of Canadian tolerance with charges of bigotry and prejudice among the white population.

Racial unease has spread since the 1960s, when Canadian immigration policies, which previously favored Anglo-Saxons and other whites, were altered to admit more immigrants from the Caribbean and Asia -- including East Indians, Pakistanis and Chinese -- among the 100,000 annual newcomers. e

In contrast to the historic melding of cultures characterized by the U.S. "melting pot," immigrants to Canada have prided themselves on their maintenance of traditional ways and values. This has been particularly pronounced in Toronto, where distinct Portuguese, Italian, Chinese and Jamaican neighborhoods have in the postwar years helped make the city of 2.9 million one of the continent's liveliest.

Until recently, this mixing of cultures and races has been achieved with remarkably little turmoil, but recent outbreaks between whites and some of the city's estimated 100,000 blacks have raised fears that the liberal tradition of earlier years is giving way to an era of conflict. Some observers have even gone so far as to predict serious racial conflict if relations are not improved.

In one recent year, racial incidents in Ontario almost tripled, according to a government study. The racial friction ranged from name-calling to physical attacks.

Much of the discrimination has been directed toward Toronto's South Asian communities, which have reacted with increasing calls for protection -- or retaliation. In a typical case earlier this summer, three youths assaulted a Pakistani family, and shortly thereafter a group of East Indians armed with bats and hockey sticks attacked a group of whites.

Toronto authorities have responded with a wide-ranging plan to increase youth employment, counter schoolyard racism, improve police relations with minorities and provide a telephone hot line so East Indian immigrants can telephone authorities immediately when racial attacks occur.