Israeli attacks in northern Gaza killed at least 12 people and injured around 30 on Thursday, the Palestinian news agency WAFA reported.
Citing medical sources, the agency said an Israeli strike hit a former school building being used to shelter displaced people in the Al-Shati refugee camp.
The Israeli military said it was investigating the reports, which could not be independently verified.
An Israeli military spokesman called on residents in the area and other neighbourhoods of Gaza City to evacuate.
The area is again a combat zone, with the Israeli military saying terrorist groups were firing rockets towards Israel.
WAFA also reported further deaths across the Gaza Strip, including in the southern city of Rafah and the northern Jabalia refugee camp.
At least 10 Palestinians were also reported killed in the central Nuseirat refugee camp.
The Israeli military said it was investigating the reports.
