Three doctors were killed in a strike at northern Gaza's Al-Awda Hospital, according to Doctors Without Borders.

The hospital said only medical personnel, patients and the injured were inside the facility at the time.

Hospital officials called on the international community to provide a safe corridor for the evacuation of patients and medical staff.

"We mourn the loss of our colleagues," Doctors Without Borders said in a statement. "We condemn this strike in the strongest terms, and call yet again for the respect and protection of medical facilities, staff and patients. We reiterate our call for an immediate cease-fire to prevent more deaths in Gaza."

Israel hopes to secure the release of at least 50 hostages within four days, according to a senior Israeli official with knowledge of the negotiations.

The official told ABC News on Tuesday that all Israeli security forces and agencies are in favor of the proposed deal with Hamas, which was brokered by Qatar.

For two weeks, Israel was against accepting Qatar's original offer, the official said. Among other things, the government did not want to allow people to return to northern Gaza during the cease-fire period, the official said. Israel also wanted to limit the entry of fuel into Gaza to only the days of the cease-fire, according to the official.

-ABC News' Jordana Miller

A U.S. official told ABC News the hostage deal would involve Hamas releasing 50 women and children in exchange for a pause in fighting that would last four or five days. The deal would also involve the release of three Palestinian prisoners for each Israeli hostage, the official said.

The Palestinian prisoners are not considered hostages. Some of them were imprisoned prior to the conflict.

The official cautioned that the deal is not done. President Joe Biden has been personally involved in the negotiations, urging the emir of Qatar to press Hamas to accept the deal and urging Israeli Prime Minister Benjamin Netanyahu to accept the deal, according to the official.

-ABC News' Selina Wang

President Joe Biden said Tuesday that "we're now very close" on a deal to release the hostages being held by Hamas, but the president did not discuss more details.

"We could bring some of the hostages home very soon, but I don't want to get into the details of things because nothing is done until it's done. And when we have more to say we will, but things are looking good," Biden said.

-ABC News' Molly Nagle

Hamas has accused the Israeli military of arresting the director of Al-Shifa Hospital, the largest medical complex in the Gaza Strip, along with several other staff members "who remained at the facility to help patients and wounded evacuate."

"We see this move by Israel as nothing less than despicable, lacking any sense of humanity and morals," Hamas said in a statement on Thursday morning. "It is also a flagrant violation of international norms and charters, given obligations to ensure that medical personnel are never harmed, including in times of war."

Hamas noted that Al-Shifa Hospital's director, Dr. Muhammad Abu Salamiya, was in contact with International Committee of the Red Cross and the World Health Organization "to evacuate the remaining patients and wounded." The militant group, which rules Gaza, called on the ICRC, the WHO and other international bodies "to exert pressure on the Israeli occupation army to secure his release, along with the medical personnel who were arrested simply for continuing to fulfil their humanitarian duty."

In a separate statement on Thursday, Gaza's Hamas-run Ministry of Health said the arrests occurred Wednesday as the United Nations and its health arm, the WHO, led a convoy of evacuated patients and medical staff from Al-Shifa Hospital. Israeli soldiers "stopped the convoy at a checkpoint separating the northern and southern Gaza Strip for seven hours" before arresting the hospital director and other staff members, according to the health ministry.

"The [Israeli] occupation bears full responsibility for the lives and safety of detained colleagues," the ministry added. "The United Nations bears full responsibility for what happened, and we await measures on their part to address this. We decided to stop coordination with the World Health Organization until a report on what happened was submitted and all detainees were released."

There was no immediate confirmation of the event or comment from the U.N. or the WHO.

There was also no immediate confirmation of the arrests or comment from the Israel Defense Forces, which has been conducting a ground raid of Al-Shifa Hospital in Gaza City for days.

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' Nasser Atta and Morgan Winsor