Those deaths, along with at least three Palestinians killed in separate Israeli air strikes elsewhere in the enclave, brought Friday's toll to at least 12, medics said.
The Awda Hospital in the Nuseirat refugee camp said seven people were killed in the attack, saying people were struck at the funeral for a Palestinian killed in a strike earlier on Friday.
In the earlier attack, which killed two people, the Israeli military said it targeted a Hamas militant.
Hamas condemned the Nuseirat strike as a "brutal massacre" against mourners and urged mediators as well as the United Nations to act to halt Israeli attacks in the enclave.
Asked about the attack in Nuseirat, the Israeli military said it struck a cell belonging to the Islamic Jihad militant group, which holds sway in parts of the Gaza Strip along with Hamas.
The military said it was "aware of the claims that several uninvolved individuals were harmed as a result of the strike".
Residents in an area east of Deir al-Balah in the central Gaza Strip said Israeli forces used drones to broadcast audio messages ordering them to leave their homes, forcing some families to flee for safety.
The deaths add to a toll of more than 1100 Palestinians, mostly civilians, killed by Israeli attacks since an October ceasefire between Israel and Hamas militants took effect, according to Gazan health officials.
Hamas does not usually disclose its losses.
The truce halted major fighting but has not stopped near-daily Israeli strikes.
Israel says it is targeting militants.
Four Israeli soldiers have been killed by militants in the Gaza Strip over the same period.
Conflict monitor ACLED, a US-based research group that tracks political violence, said Israeli air strikes against Hamas and other militants rose to more than 40 in June, the highest monthly total since the ceasefire.
Other strikes hit people near the line dividing the two sides, killing and injuring civilians including women and children, it said.
The war began when Hamas-led fighters attacked southern Israel on October 7, 2023, killing 1200 people and taking about 250 hostages, according to Israeli tallies.
Israel's subsequent offensive has killed more than 73,000 Palestinians, according to Gazan health officials.
Nearly all of the Gaza Strip's two million people now live on a tiny strip of land along the coast, mainly in makeshift tents or damaged buildings, under Hamas control.
with AP
