A Washington, D.C., nurse and at least six of her colleagues who lived through the massacre of Palestinian civilians in two refugee camps here say they want to go to Israel to testify before the commission investigating the killings.

[The three-man commission began its inquiry in Tel Aviv Monday after advertising in the Israeli media for anyone with information about the massacre to contact it.]

Ellen Siegel, 40, who arrived in Lebanon shortly before the massacres occurred Sept. 16-18, said she felt it was "a duty" for her to appear before the commission to tell what she knows about what she called "a crime against humanity."

Siegel lived through both nights of the massacre at Gaza Hospital in Sabra camp which, was swamped with 4,000 refugees seeking shelter.

She and 19 other foreign doctors and nurses were finally ordered to leave the hospital Saturday morning Sept.18 by soldiers wearing the uniforms of the Christian Lebanese Forces militia.

So far as is known, they were the only civilian foreigners, aside from two others who stayed on at the hospital who were in the camps during the massacres.

Siegel, who spent four months in Lebanon two years ago, said she had come here in early September "as an act of solidarity with the Palestinian people" whose cause she has supported for a decade.

Siegel, who works at the Washington Hospital Center, said she was active in the Palestine Aid Society, a support group in Washington, and also worked before coming here with a Jewish organization opposed to the Israeli invasion of Lebanon.

"I'm Jewish. I recognize the existence of the state of Israel but I don't recognize the Begin-Sharon government nor the treatment of the Palestinian people in the West Bank," she said, referring to Israeli Prime Minister Menachem Begin and Defense Minister Ariel Sharon. "Israel needs to recognize the PLO [Palestine Liberation Organization] and a just solution must be found for the Palestinian people," she added.

Siegel said she had been told by PLO officials she saw in Damascus before arriving here that they were eager to have foreign nurses and doctors at Gaza hospital to "act as buffers" and help protect the civilians in the camp.

Siegel still lives at the hospital and said she plans to stay on for another three months to help keep it going.

Siegel and three colleagues said in an interview at the hospital that they had evidence to give concerning the Israeli involvement with the Christian militiamen in the massacres that took hundreds of lives.

They said they would testify that Israel fired flares over the camps both Wednesday and Thursday night, Sept. 15 and 16, and shelled the camps. They also plan to testify that Israeli soldiers were just outside and at an observation post overlooking the camps and that dark-skinned people who may have been oriental Jews visited the hospital that Friday.