An Israeli air strike has killed 10 members of Hamas chief Ismail Haniyeh’s family in northern Gaza’s Shati refugee camp, according to the Palestinian group and the enclave’s civil defence agency.

Confirming the attack on the Haniyeh family and the number of the dead, Hamas said on Tuesday that it held the administration of US President Joe Biden responsible for the continuation of the war of “extermination” against the Palestinian people in the Gaza Strip.

It said the United States was continuing to give Israel “political and military cover and time to accomplish the task of destruction and extermination in the Strip”.

Mahmud Basal, a spokesman for the civil defence agency, told the AFP news agency that the Tuesday morning attack targeted the Haniyeh family home in Shati.

“There are 10 martyrs … as a result of the strike, including Zahr Haniyeh, sister of Hamas political bureau chief Ismail Haniyeh,” Basal said, adding that a number of bodies were likely still under the rubble but “we do not have the necessary equipment” to extract them.

Civil defence crews transferred the bodies to al-Ahli Hospital in nearby Gaza City, Basal said, also reporting “several wounded” in the attack.

In a statement, Hamas called “on the international community and the United Nations to shoulder their responsibilities towards these ongoing horrific crimes, to take urgent action to protect innocent civilians, and to hold the terrorist leaders of the occupation accountable for their crimes”.

The Israeli military said two buildings were targeted overnight in Shati and Daraj Tuffah, claiming that fighters who had been involved in the October 7 attack on Israel, ahead of the current conflict, were hiding inside. Its statement posted on social media did not mention striking the Haniyeh family home.

Al Jazeera’s team on the ground said the dead from the Haniyeh family included Zahr Abdel Salam Haniyeh, Nahed Haniyeh Abu Ghazi, Iman Haniyeh Umm Ghazi, Ismail Nahed Haniyeh, Muhammad Nahed Haniyeh, Moamen Nahed Haniyeh, Zahra Nahed Haniyeh, Amal Nahed Haniyeh, Shahad Nahed Haniyeh and Sumaya Nahed Haniyeh.

‘Killing and maiming’ of civilians

In April, an Israeli air strike in central Gaza killed three sons and four grandchildren of Haniyeh, with the military accusing them of “terrorist activities”.

Haniyeh at the time said that about 60 members of his family had been killed since Israel’s war on Gaza broke out on October 7 last year. The war has killed more than 37,600 people in the territory.

Israeli Prime Minister Benjamin Netanyahu has said the war will continue even if a ceasefire deal is agreed to with Hamas.

Haniyeh on Tuesday issued a statement, saying any ceasefire proposal that does not guarantee an end to Israel’s offensive in Gaza is “not an agreement”.

“If the criminal enemy thinks targeting my family will change our position or that of the resistance, they are delusional,” the statement read.

His comments come as Gaza’s Civil Defence spokesperson Mahmoud Basal told Al Jazeera that Israeli forces have deliberately targeted five displacement camps within less than 48 hours.

It also comes as UN Relief and Works Agency for Palestinian Refugees (UNRWA) chief Philippe Lazzarini reiterated warnings about the deteriorating humanitarian situation in Gaza.

The humanitarian situation in southern Gaza has “significantly deteriorated” since the Israeli army’s incursion into Rafah last month, he said, adding, “the risk of famine in Gaza continues”.

Moreover, he said more has to be done to tackle the crisis on the ground, including a ceasefire and the scaling up of humanitarian aid across Gaza.

At least 10 Palestinians, including guards securing aid trucks, have been killed in an Israeli attack on people seeking aid supplies in southern Gaza’s Khan Younis on Tuesday.

According to Moureen Kaki, logistics coordinator for medical group Glia, the situation in hospitals across the besieged coastal enclave has also become more dire with the Israeli closure of the vital Rafah border crossing on May 7.

Medical personnel “don’t have the supplies they need to treat critically injured patients. They themselves are exhausted, and on top of that, they are dealing with injuries at levels that they don’t have the materials for,” she told Al Jazeera.

“We’re not even talking about people with chronic illnesses like cancer, [or who have needs] like dialysis. We’re talking about people stablising patients who are otherwise going to die,” Kaki said.

Also on Tuesday, the UN’s Middle East envoy Tor Wennesland sounded the alarm about the dire humanitarian situation in Gaza.

In a UN Security Council briefing, Wennesland condemned the “killing and maiming of civilians in Gaza, including women and children”.

“Israel’s use of explosive weapons in densely populated areas has destroyed entire neighbourhoods and damaged hospitals and other civilian infrastructure, schools, mosques and United Nations premises,” he said.