Rep. Harold Washington (D-Ill.) said today that his Republican opponent in the mayoral race, Bernard Epton, bears "the ultimate responsibility" for an ugly incident outside a church in a white neighborhood on Palm Sunday.

"You can draw your own conclusions as to who inspired what happened," said Washington, the first black ever to win the Democratic mayoral nomination here. "But no matter who inspired it, one is responsible for the actions of his agents. If one comports themselves in such a way that, in effect, stimulates that kind of activity, you have to take ultimate responsibility."

Epton, who originally entered the race to provide only token opposition, responded that he was "appalled" by the disturbance, and disavowed any connection with it. He accused Washington of using smear and "innuendo tactics" in blaming him for "an unfortunate situation."

He also noted that a worker in one of his neighborhood campaign offices was beaten by blacks last week. With the April 12 election only two weeks away, Washington, a two-term congressman from the South Side, has found himself in what appears to be a surprisingly close race with Epton.

There is a widespread feeling among political observers here that Washington has failed to take the offensive or reach out to the 60 percent of Chicago voters who are white.

And each day brings new reminders of the racial issue in this election.

Rep. Claude Pepper (D-Fla.), one of a series of national party figures who have come to town to campaign for Washington, was greeted with both boos and applause today when he endorsed Washington at a senior citizens' gathering in a predominantly white area.

"This is America," said Pepper, a leading spokesman for the nation's elderly. "It isn't the color of a man's skin that matters. It's character."

Pepper, a veteran of 30 years in Congress and one of the Democratic Party's most seasoned politicians, later offered Washington a piece of advice that many here agree with. He said that if he were running for mayor he would spend "the rest of my time going from group to group" in the city seeking support.

"I hope he Washington can get out with these people, to shake their hands and look them in the eye."

A crowd of about 150, many wearing "Epton for Mayor" buttons and waving Epton signs, jeered and booed Washington and former vice president Walter F. Mondale when they tried to attend Palm Sunday Mass at St. Pascal Catholic Church on the northwest side of the city.

The Republican nominee, a former state legislator, didn't campaign today because of the Jewish holidays, but his staff met to discuss how to deal with the church incident. Press secretary Judy Knapton said Epton aides had reviewed television film of the church scene and went to the neighborhood to investigate whether anyone connected with the campaign was in the disturbance.

She said the only heckler that Epton aides could identify was a man they had thrown out of Epton's downtown headquarters for using racist language. "There's nothing we can do about yahoos," she said.

Knapton and others in the Epton camp point out that the Republican candidate has asked Washington repeatedly to meet with him and issue a joint statement disavowing "any and all appeals for support based on race or religion." Washington refused to acknowledge the request.

Both sides have been blamed for making race the overriding issue in the mayor's contest in this racially divided city of 3 million people, 40 percent of whom are black.

Epton's television ads urge a vote for the Republican "before it's too late." And Epton, who is Jewish, has said that if Washington were "the best candidate my ethnic group could produce I'd be ashamed."

Washington, who relied almost totally on black votes to win a three-way primary, has warned of a "race war" that "might turn bitter, evil, angry."

The Rev. Francis Ciezadlo, pastor of St. Pascal Church, said today that the crowd of Sunday hecklers was made up of "neighborhood people," including about 25 members of his congregation.

"They're all hard-working, middle-class people. Some left the West Side after blacks moved in, and they associate blacks with fear," he said. "They're afraid Mr. Washington's election would mean change that would damage the neighborhood. They're afraid he would bring in public housing."

Cardinal Joseph L. Bernardin said today he was "saddened by the hostility" shown to Washington and Mondale. "Even when differences of opinion exist, Christians should demonstrate civility and the charity of Christ."