D.C. Mayor Marion Barry, attending a National League of Cities conference here, said today that the violence that erupted after the abbreviated Ku Klux Klan rally in Washington Saturday was "an isolated event" that should not have any lasting effect on the image of the city.

Barry also dismissed suggestions that the violence might alarm local businesses or that the violence occurred because of inadequate police protection.

Asked about his decision to leave Washington before the demonstrators were completely dispersed, Barry said he had been in constant contact with Police Chief Maurice Turner, who had assured him that "the situation was under control."

"I talked to him at 4:30 p.m. Saturday," Barry said yesterday. "If the situation weren't under control I would have stayed." Barry flew to Los Angeles from Dulles Airport at about 5:30 p.m. for the NLC conference which continues through Wednesday. The violence had largely subsided by 3:30 p.m.

"It's a false issue (leaving Washington)," Barry said. "The issue is the hatred of the Klan that prompted those actions . . . I'm only five hours away, I'm in constant contact. I never leave Washington emotionally, even if I'm physically somewhere else."

Barry said he did not fault the police handling of the incident, which included looting of some stores and smashing of storefront windows. "They were prepared for everything," Barry said.

"Chief Turner has more than 20 years of experience. He's seen demonstrations of all kinds. He's seen the Weathermen, he's seen the anti-war demonstrations, the Iranians, he's seen me," Barry said in a reference to his own street activist days in Washington.

"It's my own judgment that the situation was under control," the mayor said. "I didn't like the fact that we were protecting the Klan. I didn't like the fact that we were protecting Iranian students when they had our people in jail. We have to do it."

City Council chairman-elect David A. Clarke (D-Ward 1) who accompanied Barry here, said he too thought the police had the demonstration under control before the officials left the city. Clarke said he had personally witnessed some of the violence that occurred around McPherson Square and Lafayette Park.

The violence was front page news in the Los Angeles Times which also ran four pictures of the events.

D.C. City Council member Nadine P. Winter (D-Ward 6) said many of the delegates here had asked her about the aftermath of the demonstration. Winter said she has been in Los Angeles since last Thursday, but said Barry told her today that the situation was under control.

Winter, who is lobbying Clarke to become chairman of the council's judiciary committee in January, said she would have liked to have seen the city stop the Klan march because of the opportunity for violence. She said the Klan could not be compared to civil rights groups because those groups demonstrated in support of equal rights rather than against them.

Former Atlanta Mayor Maynard Jackson, now a lawyer in private practice, said in an interview here that he thought the Klan "is a terrorist organization and ought to be outlawed. I think it's a criminal organization and ought to be prosecuted," Jackson said. "But I don't believe in violence of any kind."

Jackson, who spoke briefly with Barry about the incident declined to say whether he thought the city should have banned the march.