At least seven children were killed by an Israeli strike in broad daylight while waiting in line for nutritional supplements near a medical centre in central Gaza on Thursday, health officials say.

The bodies of the children, covered in blood, were lined up along the floor of Al-Aqsa Martyrs Hospital as relatives came up to hold them one by one.

Gaza's Health Ministry said the attack in Deir al-Balah happened at around 9:15 a.m. on Thursday, killing at least 15 people, including seven children between one and 14 years of age.

Abu Hassan Bashir, 38, was in the area at the time of the strike and rushed to help at the scene of the attack.

"I held two children who were martyred," Bashir told CBC News freelance videographer Mohamed El Saife.

"This small Zionist rocket ripped apart the children and turned them into martyrs," he said, pointing at a small crater in the ground which appeared to have been left after the strike.

He also pointed to the blood stains covering the curbs at the site, where children's slippers had been left behind, adding that most days, the line of women and children standing there was much longer than the one on Thursday morning.

"If [Israeli Prime Minister Benjamin] Netanyahu delayed the strike a bit, there would have been 100 martyrs because of how busy it gets here," Bashir said, adding that medical centre provides nutritional supplements and ailment treatment for children and pregnant women.

Project Hope, an aid group that runs the humanitarian facility at the site of the strike, confirmed the deaths on Thursday.

"No child waiting for food and medicine should face the risk of being bombed," said Dr. Mithqal Abutaha, the group's project manager, who was at another clinic at the time. "People had to come seeking health and support. Instead, they faced death."

Families' screams fill hospital halls

In Al-Aqsa Martyrs Hospital, where those wounded and killed in the attack were taken, families' cries filled the halls.

Nidal Al-Nouri said he was talking to his 14-year-old daughter Sama yesterday about their hopes for a ceasefire to take place to be able to return to school.

"Sama's gone and the war remains. God willing this war will end with her death," he said.

Israel claimed that in its Thursday attack, it had struck a militant who took part in the Oct. 7, 2023, Hamas-led attacks that triggered the war, although the military didn't provide evidence. It said it was aware of reports regarding a number of injured individuals and that the incident was under review.

Videos on Thursday verified by Reuters showed a scene of carnage, with the bodies of dead and injured, mainly women and children, lying in blood amid a cloud of dust as people screamed all around.

Khalil al-Deqran, spokesperson for Gaza's Health Ministry, said many of those injured in the attack had suffered severe wounds to the head and chest.

Samah al-Nouri said her daughter had been killed in the morning's strike after attending the clinic to seek treatment for a throat ailment.

"They hit her with a shell. Her brother went to check and he said they all died," she said. "What did they do? What's their fault? She was only getting treatment in a medical facility. Why did they kill them?"

Hospitals face dire fuel shortage

Israeli attacks on Palestinian hospitals and health facilities, detentions of medics and restrictions on the entry of medical supplies have drawn condemnation from the United Nations.

The UN humanitarian agency OCHA said in May that it had documented at least 686 attacks impacting health care in Gaza since the war began.

Meanwhile, dwindling fuel supplies risk further disruption in the semi-functioning hospitals that remain as deaths mount in the territory. Doctors said they are being forced to place up to five premature babies who are in critical condition in one incubator due to the imposed shortage of fuel in Gaza.

WATCH | Gaza ceasefire deal not likely to be secured this week: 

Israel, U.S. signal Gaza truce may take more time, possible in 1 or 2 weeks

Israeli and Hamas negotiators are holding talks with mediators in Qatar over a proposed 60-day ceasefire and hostage release deal. However, a senior Israeli official said on Wednesday that an agreement was not likely to be secured for another one or two weeks.

A UN team got about 75,000 litres of fuel into Gaza on Wednesday, the first such delivery in 130 days, said UN spokesperson Stephane Dujarric on Thursday.

"The amount entered yesterday isn't sufficient to cover even one day of energy requirements. Fuel is still running out and services will shut down if far greater volumes do not enter immediately," Dujarric told reporters.

The latest deaths come as Israeli and Hamas negotiators hold talks with mediators in Qatar over a proposed 60-day ceasefire and hostage release deal aimed at building agreement on a lasting truce.

However, a senior Israeli official said on Wednesday that an agreement was not likely to be secured for another one or two weeks.

Israel's military campaign in Gaza has killed at least 57,680 people, according to Palestinian health authorities. It has destroyed swaths of the territory and driven most Palestinians from their homes, displacing them multiple times in the 21-month-long war.

The Hamas attack on Israeli border communities that triggered the war killed around 1,200 people and the militant group seized around 250 hostages, according to Israeli tallies.