The attack took place in Muwasi, the area designated by Israel as a humanitarian zone.
An Israeli strike on a tent camp in Gaza early on Tuesday killed at least 40 people and wounded 60, Palestinian officials said.
Israel said it targeted “significant” Hamas militants and disputed the death toll.
The figures would place the attack among the deadliest yet in Muwasi, a sprawl of crowded tent camps along the Gaza coast that Israel has designated as a humanitarian zone.
Gaza’s Civil Defense said first responders recovered 40 bodies from the strike and that entire families were killed in their tents.
An Associated Press camera operator recounted seeing first responders and displaced people pulling body parts from sand and rubble, sifting through with garden tools and their bare hands by the light of mobile phones.
Nasser Hospital in Khan Younis, one of three hospitals to receive casualties, said around two dozen bodies were brought in from the strike.
