The United Nations Relief and Works Agency for Palestine Refugees in the Near East warned on Thursday that hundreds of thousands of Palestinians in Gaza are still sheltering in "overcrowded" schools as Israel's 15-month war on the enclave continues.

"Playgrounds for children are homes for the displaced," UNRWA wrote on X. "More humanitarian aid must come into Gaza and a ceasefire is more critical than ever."

UNRWA facilities in Gaza have been attacked frequently since the Israeli invasion began, as have school buildings doubling as shelter for Gazans displaced by the fighting.

The vast majority of Gaza's pre-war population of 2.2 million has been displaced at least once since the fighting began.

-ABC News' Joe Simonetti

The Palestinian Ministry of Health in Hamas-run Gaza announced that 46,006 people have been killed in Gaza since the war with Israel began on Oct. 7, 2023.

The number of injured rose to 109,378, officials said Thursday morning.

At least 70 people were killed in the past 24 hours, the ministry said, and 104 more were injured by Israeli strikes across the Palestinian territory.

-ABC News' Joe Simonetti

U.S. Central Command conducted "multiple precision strikes" against two Houthi underground storage facilities in Yemen on Wednesday, the command said in a statement.

"The Houthis used these facilities to conduct attacks against U.S. Navy warships and merchant vessels in the southern Red Sea and Gulf of Aden," CENTCOM said. "There were no injuries or damage to U.S. personnel or equipment."

U.S. and British forces -- backed by a range of allies -- have been bombing the Iran-aligned Houthi organization in Yemen since January.

The strikes are a response to Houthi attacks on commercial and military shipping in the Red Sea and elsewhere, launched in protest of Israel's war in Gaza. The Houthis have also launched direct attacks on Israel and vowed to continue to do so while the war in Gaza continues.

Israel has launched several waves of strikes on Yemen in response. Prime Minister Benjamin Netanyahu said last month that Israel would continue to act against the Houthis "with force, determination and sophistication."

Families of American hostages who are still believed to be held in Gaza will attend President-elect Donald Trump's inauguration later this month, a release from the families said Wednesday.

"During the trip, the families plan to meet with officials from the incoming Trump administration, along with members of Congress and their staff," the release said.

"The families are urging leaders to prioritize the safe return of their loved ones and to take decisive action to bring an end to their prolonged captivity," it added.

There are seven American hostages still believed to be held captive inside Gaza, according to the families.

Trump said this week that "all hell will break out in the Middle East" if the remaining Gaza hostages are not released before his inauguration on Jan. 20.

-ABC News' Nadine Shubailat and Ellie Kaufman