Medical staff at al-Awda Hospital in Nuseirat said 30 bodies were brought in after the attacks.
The condition of the victims made identification difficult, they added.
At least eight of the dead were reportedly members of the same family. Eyewitnesses reported multiple Israeli strikes on residential buildings north of Nuseirat.
The information could not be independently verified, and the Israeli military has so far not commented on the reports.
The attack came just days after the Israeli military, under growing international criticism over the dire humanitarian situation in embattled Gaza.
The report said it would observe daily 10-hour humanitarian pauses in parts of the Strip where its troops are not operating.
These included al-Mawasi in the south-west, Deir al-Balah in the centre, and Gaza City in the north. (dpa/NAN)
