Attack levels a multistorey residential building, with many people trapped under the rubble and rescue efforts hampered.

An Israeli air attack has killed at least 73 Palestinians, including women and children, in Beit Lahiya in the northern Gaza Strip, the authorities said, describing it as a “massacre”.

The overnight strike hit several houses and a multistorey residential building, known as the Beit Lahiya Project, the Gaza Government Media Office said, as many people remained trapped under the rubble on Sunday.

Rescue efforts have been hampered by a communications blackout and road obstructions in the north of the enclave, where a 16-day Israeli military siege has cut off access to food, water, medicine and essential services for residents.

Beit Lahiya is a city located in the far north of the Gaza Strip close to Jabalia and Beit Hanoon. All three cities are severely affected by the Israeli offensive that has also resulted in severed phone and internet access.

Reporting from Deir el-Balah in central Gaza, Al Jazeera’s Hani Mahmoud said “the extent of the brutality of the latest attack” in Beit Lahiya keeps unfolding, “with many people still buried under massive piles of rubble”.

“A witness from the area described the massive explosion resulting from multiple air strikes shaking the very foundations of the surrounding areas,” he said.

Mahmoud said large chunks of concrete have blocked the path to the bombed-out areas, making it difficult for paramedics and Palestinian Civil Defence members to conduct rescue missions in Beit Lahiya, resulting in more casualties, the majority of them women and children and elderly.

“More than half of the people who were killed are, in fact, people who were forced to evacuate from Jabalia and other parts” of northern Gaza under Israeli siege, he noted.

Among those killed in the attack in Beit Lahiya were at least 10 relatives of Al Jazeera Arabic’s correspondent Anas al-Sharif.

“Today, while covering the massacre by Israeli occupation forces in [Beit Lahiya], I was shocked to discover that one of the homes targeted in the airstrike belonged to my cousin,” al-Sharif wrote in a post on X.

An earlier Israeli military strike in Jabalia killed at least 33 Palestinians. Residents and medics said Israeli forces have been tightening their siege on the Jabalia refugee camp, the largest of the enclave’s eight historic camps.

Jabalia residents said Israeli forces besieged several shelters housing displaced families before they stormed them and detained several men. Footage on social media showed dozens of Palestinian men sitting on the ground next to a tank, while others were led by a soldier to a gathering site.

The attack in Beit Lahiya came after Gaza health officials said three partially functioning hospitals treating severely wounded patients and sheltering thousands of displaced Palestinian civilians in northern Gaza were now out of service after coming under intense Israeli fire.

Israeli forces bombed al-Awda Hospital in Jabalia early on Saturday, and have also shelled Kamal Adwan and Indonesian hospitals in Beit Lahiya over the past few hours, Al Jazeera correspondents reported.