At least 17 Palestinians were killed and 50 were wounded in Israeli strikes on Gaza City in the early hours of Sunday morning, civil emergency and health officials said.

The fatalities resulted from at least four separate Israeli airstrikes on four houses in different areas of the city. Residents and Palestinian health officials said the Israeli military had stepped up aerial and ground shelling.

On Saturday an Israeli airstrike killed at least 90 Palestinians in a designated humanitarian zone in Gaza, the enclave’s health ministry said. The attack was the deadliest in Gaza for weeks.