The director of one of north Gaza's largest hospitals was killed, along with his wife, daughter and sister, in an Israeli strike on their apartment, medical officials said Wednesday.

Dr. Marwan Sultan was the director of the Indonesian Hospital — the largest medical facility north of Gaza City and a critical lifeline for civilians in the area since the start of the nearly 21-month-long war in the territory.

Diaa Al-Najjar, Sultan's nephew, said his uncle never stopped working amid the war, even for a moment.

"He kept resisting. Until the last second, the last moment," Al-Najjar told CBC News in Gaza City. "May God grant us patience and may God have mercy on our martyrs."

The bodies of Sultan and his family arrived at Shifa Hospital in pieces, according to Issam Nabhan, head of the nursing department at the Indonesian Hospital. 

"Gaza lost a great man and doctor," Nabhan said. "He never left the hospital one moment since the war began, and urged us to stay and provide humanitarian assistance. We don't know what he did to deserve getting killed." 

1,500 health-care workers killed since 2023

The hospital was surrounded by Israeli troops in May, and evacuated alongside the other two primary hospitals in northern Gaza, after Israeli forces renewed their offensive in the region, saying at the time it was targeting Hamas infrastructure.

Only 20 of Gaza's 36 hospitals were partially functioning in May, while others were forced to shutter as a result of damage from Israeli strikes.

Médecins Sans Frontières (MSF) and other aid groups have accused Israel of targeting hospitals and condemned the attacks and arrests of medical workers.

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Munir Al-Barash, general director of Gaza's Health Ministry, said the killing of Sultan is the latest death in a long list of health-care workers targeted in the Gaza Strip.

"Dr. Marwan Sultan was under [Israeli army] siege in the Indonesian Hospital ... and he insisted on continuing operations and did not stop," Al-Barash told CBC News freelance videographer Mohamed El Saife on Wednesday outside Al-Shifa Hospital in Gaza City.

"The Israeli [military] is targeting medical figures."

More than 1,500 healthcare workers have been killed in Gaza since October 2023, according to the Gaza Ministry of Health.

The ministry also said the death toll in Gaza passed the 57,000 mark Tuesday into Wednesday, after hospitals received 142 bodies overnight. 

Since dawn Wednesday, Israeli strikes killed a total of 40 people across the Gaza Strip, the Health Ministry said. Hospital officials said at least four children and seven women were among the dead. 

The Israeli military said it was looking into the reports.

The war began on Oct. 7, 2023, when Hamas-led militants attacked southern Israel, killing 1,200 people and taking roughly 250 hostages.

The war has left the coastal Palestinian territory in ruins, with much of the urban landscape flattened in the fighting. More than 90 per cent of Gaza's 2.3 million population has been displaced, often multiple times. And it has sparked a humanitarian crisis in Gaza, pushing hundreds of thousands of people toward hunger.

Hamas reviewing Trump-backed ceasefire plan

The latest deaths in Gaza come as Hamas said it was studying what U.S. President Donald Trump called a "final" ceasefire proposal for Gaza.

Trump had said Tuesday that Israel had agreed to the conditions needed to finalize a 60-day ceasefire with Hamas after what he described as a "long and productive" meeting between his representatives and Israeli officials.

In a statement, Hamas said it was studying new ceasefire offers it received from the mediators Egypt and Qatar but stressed it aimed to reach an agreement that would ensure an end to the war and an Israeli pullout from Gaza.

Israeli Prime Minister Benjamin Netanyahu called for the elimination of Hamas in his first public remarks since Trump's announcement.

"There will not be a Hamas. There will not be a Hamastan. We're not going back to that. It's over," Netanyahu told a meeting hosted by the Trans-Israel pipeline.