Gaza's civil defence agency said Israeli strikes overnight and early Sunday killed at least 28 Palestinians, including at one family's home and at a school building the military said was used by Hamas.

Civil agency spokesman Mahmud Bassal said in a statement that at least 13 people were killed in an air strike on a house in central Gaza's Deir el-Balah belonging to the Abu Samra family. There was no immediate comment from the Israeli military, which has confirmed a separate strike further north, on a school in Gaza City.

Bassal said that eight people including four children were killed in the attack on the school, which had been repurposed as a shelter for Palestinians displaced by the war. The Israeli military said it had carried out a "precise strike" overnight targeting Hamas militants operating there.

A military statement said that a Hamas "command and control centre... was embedded inside" the school compound in the city's east, adding that it was used "to plan and execute terrorist attacks" against Israeli forces. Contacted by AFP, an Israeli military spokesperson said they were unable to immediately comment on other reported strikes elsewhere in Gaza.

Bassal said an overnight strike killed three people in Rafah, in the south. And a drone strike early on Sunday hit a car in Gaza City, killing four people, Bassal said.