Washington (AFP) - Four-year-old American hostage Abigail is surrounded by family in Israel who "brought her life back" after seven weeks of captivity, her great aunt said Wednesday, as relatives stressed they will not rest until everyone held by Hamas is freed.

The young girl, whose parents were murdered in front of her on a kibbutz near Gaza as militants stormed Israel on October 7, is the first confirmed US citizen to have been freed by Hamas among the 60 hostages released during an extended truce.

Great aunt Liz Hirsh Naftali stressed that while "it's a miracle" Abigail is safely with loved ones after her Sunday release, families of hostages were in Washington to shine a spotlight on the more than 150 people who still remain in captivity in Gaza, a sum believed to include nine other Americans.

It is important for families and released hostages "to keep fighting for the rest of the people who are held captive," Hirsh Naftali told a news conference in the US capital.

Several parents testified later that day before a US congressional subcommittee about the need for faster action.

She also spoke of the struggle ahead for all of the hostages, as they come to grips with the "horrific" ordeal.

Abigail is "doing OK because she has that loving family," said Hirsh Naftali, who also revealed shocking details about how the girl survived after her two older siblings managed to escape.

With her parents murdered, the girl hid under her father's lifeless body and then crawled out, "covered in his blood," and rushed to a neighbor, Hirsh Naftali said.

But Abigail and that family were captured and taken to the Palestinian territory.

After her return to Israel, Abigail "saw her siblings, she smiled, her cousins, they laughed. That brought her life back, that brought the shine back," Hirsh Naftali said.

"But keep in mind, we will not know for years what the effect is on any of these children or adults that have spent 50, 52, now 54 days somewhere in the dark" while being held "by Hamas terrorists."

'Living hell'

Few details have emerged of the captivity conditions in Gaza, and the families expressed frustration that the International Committee of the Red Cross, while coordinating the handover both of hostages and Palestinian prisoners released by Israel, has yet to gain access to captives in Gaza.

Hagit Chen's 19-year-old son Itay was among the more than 240 Israelis and foreign nationals seized last month. She and her husband Ruby wore matching shirts Wednesday showing their son's face and the words "Bring Itay Home Now."

"Not knowing anything about him for 54 days, it's a living hell," said Chen, a granddaughter of a Holocaust survivor.

"We feel like it's the Holocaust happening all over again," she added. "We need someone to save us, to save Itay, and to save the 150 hostages who are still in Gaza."

Ruby Chen spoke of his exasperation about the glacial pace of American releases, even as US President Joe Biden plays a key role in negotiations.

Hostages from several nations -- Germany, Russia, Thailand -- have been freed, he noted. 

"Where are the US citizens?" he asked.

Chen also said he learned some of the hostages were ordered to write thank-you letters to their captors "while they had a gun pointed at them."

Chen slammed an hourglass down onto a table and exclaimed: "We don't have time."

The relatives met earlier Wednesday with Red Cross representatives. 

"We did express our disappointment that there have been no visitation rights," Chen said.