The U.S. does not know where the last unaccounted for American woman is or what her condition is, according to National Security Council spokesperson John Kirby.

Since the cease-fire began several days ago, only one American woman and one American child have been released by Hamas.

Asked by ABC News if the U.S. believes Hamas does not know where all the hostages are -- or if they're propagating that information as a delay tactic -- Kirby said even though some other groups also took hostages, "That’s not to say that Hamas doesn’t have visibility on that, or doesn’t have a way to find out about it."

Kirby said Israel has made clear that "when these pauses are over, they intend to go back at it."

"And as they make that decision, they’ll continue to find support from the U.S. in terms of tools and capabilities, the weapons systems they need, as well as the advice and the perspectives that we can offer in terms of urban warfare," Kirby said.

He added that he believes the U.S. approach has had a "practical effect" on the way Israel is conducting its operations. Kirby said the U.S. shared experiences with urban warfare in places like Fallujah and Mosul in Iraq, and that the Israelis were "receptive" to those lessons learned.

-ABC News' Selina Wang

Thursday morning's shooting carried out by Hamas at a Jerusalem bus stop did not violate the cease-fire agreement because "this attack happened in Jerusalem" and "the pause is in the fighting more specific to Gaza," National Security Council spokesperson John Kirby said.

"It didn't technically violate the deal that was in place, but obviously it's a stark reminder of who they’re facing and what kind of enemy they’re opposing," Kirby continued.

"If anybody's guessing and wondering whether Hamas still has murderous intentions against the Israeli people, just look at what happened in Jerusalem," Kirby said.

At least three people were killed in Thursday's shooting. The two gunmen were killed by two off-duty Israeli soldiers and a civilian who were near the scene, according to Israeli police.

Hamas claimed responsibility, saying the shooting was in response to Israel's "unprecedented crimes" including "brutal massacres" in Gaza and the killing of children in the occupied West Bank.

-ABC News' Fritz Farrow

About 80% of Gaza’s population is now homeless, with many people forced to live in make-shift shelters, largely exposed to the elements, according to the United Nations.

The bad weather is compounding an already difficult situation, several Gaza residents told ABC News in interviews conducted during the last two weeks. People living in tents are struggling to make them watertight. They are patching them up as best they can with tarpaulin. The rainy season in Gaza usually begins in late November or early December and temperatures can get as low as 50 degrees Fahrenheit.

"At 6 in the morning, we woke up to rain falling and the place was soaked with water," Iqbal Saleh Mohsen Abu Al-Saud, one resident, told ABC News, when the winter rains first came to Gaza last week.

"We are 30 people in this tent,“ he explained. "We were displaced from Gaza City from the Sheikh Radwan neighborhood. We went from home to schools, then to tents, from place to place. Without food or shelter, we only left our homes because of the bombing."

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Two Israeli hostages released in the Gaza Strip -- 21-year-old Mia Schem and 40-year-old Amit Sosna -- have been transferred to the Red Cross and are now on their way to Israel, the Israel Defense Forces said Thursday evening.

More hostages are expected to be released in the coming hours, according to the IDF.

Muhammad Ibrahim Asfour was among the Gaza residents who returned home during the cease-fire to find destruction where homes used to be.

"I was shocked, and when I saw the house I started crying," Asfour told ABC News. "There were 50 people in the building here -- all of my brothers and father were living here."

"The situation here is more difficult than you can imagine," Abdelkader Darma told ABC News. "When I came home I was shocked."

"People do not know where to go," Darma said. "I and six other people slept on two mattresses and two pillows, which means you do not know how to sleep. They sleep three against three, and you find his feet in front of your face."

“I hope the truce will be extended and a solution will be found because it is enough. People are sleeping in the street," Darma said. "How can you bear it?"

-ABC News' Zoe Magee and Sami Zayara