They spoke in voices trembling with anger and loathing. The listeners sat in rapt silence, occasionally shaking their heads at a particularly horrific detail.

In a hearing room at the Capitol, six people who fled from Iraqi troops in Kuwait described for members of Congress atrocities they had seen and experienced as Iraqi President Saddam Hussein's forces moved to complete the dismantling of the occupied nation and the subjugation of its population.

It was the first airing here of extensive firsthand accounts from Kuwait, and it left a visible impression on the lawmakers, who are pondering whether the United States should mount a military offensive against Iraq, and if so, when.

The witnesses included Deborah Hadi, who recently left her Kuwaiti husband to escape to the United States, but not before she had experienced the "primitive, uncivilized behavior" of Iraqi troops. "We took our cousin, who was in labor, to Sabah Maternity Hospital. Upon our arrival, we saw a Kuwaiti woman at the front door, in hysterics, because she was in labor and they would not allow her to enter," said Hadi, pausing to fight back a sob. "When she continued to scream, they put a bayonet through her stomach, pinning her to the wall."

A 15-year-old Kuwaiti girl, who testified under an assumed name to protect family members, described a friend after he was tortured by Iraqis. "He is 22, but he looked as though he could be an old man," she said. "The Iraqis dunked his head in to a swimming pool until he almost drowned. They pulled out his fingernails and applied electric shock to his body."

Another American married to a Kuwaiti, Ruth Al-Qallaf, testified that Iraqi soldiers "are taking young Kuwaiti girls, 13, 14 and 15 years old, and raping them," an act even more devastating in a conservative society in which virginity is a prerequisite for marriage, she said.

"In the eight-year history of the Congressional Human Rights Caucus, we have never had the degree of ghoulish and nightmarish horror stories coming from totally credible eyewitnesses that we have had this time," said Rep. Tom Lantos (D-Calif.), co-chairman of the panel, which has heard testimony in the past about torture and abuses in Latin America and Africa.

{The Iraqi ambassador to the United States, Mohamed Mashat, denounced the hearing as "a circus," but acknowledged "some misconduct by Iraqi soldiers" in Kuwait, Reuter reported. At a news conference in Cambridge, Mass., Mashat said the hearing "depends on people who are coached to speak that way" and he called most of the testimony "a pack of lies."}

Hadi described to the caucus "images of death, destruction, brutality and helplessness" imprinted in her mind by the actions of Hussein's military forces. Her account was echoed by the other witnesses, some of whom said they fear for the safety of relatives they left behind.

Their testimony came a day after President Bush warned that his patience is "wearing very thin" with reported Iraqi atrocities in Kuwait. White House officials said the apparent Iraqi campaign to crush the Kuwaiti citizenry and gradually replace it with loyal immigrants was accelerating the administration's timetable for deciding on possible action.

Congress is scheduled to adjourn Oct. 19, and members have expressed eagerness to be fully apprised of possible Iraqi provocations and potential U.S. options before they leave Washington.

Kuwaiti Ambassador Sheik Saud Nasir Sabah, who also testified at the hearing, warned the legislators "time was running out" for Kuwait. "I hope we can find a quick and prompt solution to rescue my people," he said. "I don't believe that Iraq, in the short run or the long run, will be adversely affected by sanctions."

He said the people of Iraq can "sustain themselves indefinitely" because the border between Iraq and Jordan remains open, and supplies are being transported in regularly.

Rep. Ronald K. Machtley (R-R.I.), said the testimony was "some of the most emotional, hard-hitting and difficult" he had ever heard. "I left the hearing with tears in my eyes," he said.

One witness, Khaled Nassar, said a physician friend at Mubarek El Kabeer Hospital described to him how the Iraqis had converted his hospital into military barracks. "They installed snipers in the roof. . . and took all the patients, most of them very sick or very old, and forced them at gunpoint into the hospital corridors," he said his friend told him. Nassar said many patients were removed from life-support systems or prevented from receiving needed blood transfusions. "Half the patients in the hospital died," he said.