Israel-Gaza updates: IDF says it exposed Hamas tunnel under Shifa Hospital

Israeli ground troops continued to carry out a raid on the largest hospital in the Gaza Strip for a second day.

A spokesperson for the Israel Defense Forces told ABC News that, as of 1 p.m. local time on Thursday, soldiers were still inside Al-Shifa Hospital in Gaza City, some 34 hours after launching the raid.

The IDF spokesperson also confirmed that they found explosives inside the medical complex.

The IDF alleges that Hamas has placed its command centers under Al-Shifa and other hospitals in Gaza and is deliberately sheltering behind Palestinian civilians -- claims that the militant group denies.

-ABC News' Dana Savir and Morgan Winsor

Negotiations are progressing towards a U.S. and Qatari-brokered hostage release deal between Israel and Hamas, according to multiple officials in the U.S. and Israel.

The potential deal could see Hamas free dozens of Israeli hostages taken on Oct. 7 in exchange for Israel's release of jailed Palestinians and occur during a multi-day cease-fire in Gaza, the officials said.

The contours of that deal are still being worked out, including how many Israeli hostages would be released and how long a cease-fire would last.

Multiple officials in the U.S. and Israel told ABC News that the current figure is at least 50 Israeli hostages -- women, children and the elderly -- would be released, though the exact number is not yet final. This would likely take place in batches, with hostages released in exchange for a yet unspecified number of Palestinian women and minors held in Israeli jails, the officials said.

The cease-fire could last between three and seven days though the length is being negotiated and remains a sticking point, the officials said.

There would be other Israeli concessions as well, potentially including the delivery of fuel into Gaza, according to the officials.

Two U.S. officials told ABC News that an agreement seems to be within reach, but that multiple similar proposals have fallen apart just before reaching the finish line in recent weeks.

-ABC News' Matt Gutman, Jordana Miller and Shannon K. Crawford

A fuel truck crossed the Rafah border crossing from Egypt into Gaza on Wednesday, marking the first time fuel entered Gaza since Oct. 7, a spokesman for the Palestinian Crossings Authority said, according to The Associated Press.

Fuel has been drying up in Gaza as the war continued.

The United Nations Relief and Works Agency for Palestine said their trucks -- which deliver aid from Egypt to Gaza -- ran out of fuel Tuesday.

In hospitals, a lack of fuel has prevented doctors for running incubators for babies.

And without fuel, many residents of Gaza have been trapped, unable to drive south toward the Egyptian border.

At Gaza's Al-Shifa Hospital, 43 out of the 63 intensive care patients have died as oxygen in the intensive care unit runs out, according to Dr. Ahmed Mokhallalati, head of the hospital's plastic surgery department.

Mokhallalati told ABC News the mission of burying bodies is ongoing as more people die inside and outside the hospital.

Mokhallalati said he could still hear the Israeli tanks at the hospital gates Wednesday night.