Many Palestinians were seeking shelter after fleeing their homes in southern Gaza and complained of water shortages as Israel pressed on with its military offensive in the densely populated enclave.

Israeli forces carried out new strikes in the southern city of Rafah amid fierce fighting with Palestinian militants overnight, residents said. At least 12 people were killed in new strikes in central and northern Gaza, health officials said.

Tensions also rose between Israel and the Lebanese armed group Hezbollah after the latest in frequent exchanges of fire across Israel’s northern border with Lebanon since the start of the Gaza war.

Two security sources in Lebanon said an Israeli airstrike had killed a senior Hezbollah field commander, and Israel’s defence minister said Israeli forces would be ready to take any action necessary against the Iran-aligned group.

Fighting is still raging in some parts of Gaza despite Israeli leaders saying they are winding down the phase of intense fighting against Hamas, the Islamist group that has governed Gaza since 2007, and will soon shift to more targeted operations in the nearly nine-month-old war.

One Israeli airstrike hit a house in the southern city of Khan Younis, killing Hassan Hamdan, head of the burns and plastic surgery department at Nasser Medical Complex, along with all his family members, the Gaza health ministry said.

Khan Younis residents said a lack of designated shelters meant many families had slept on the road because they could not find tents after Israeli army evacuation orders led to the displacement of thousands of people living east of the city.

The last functioning hospital in the area, the Gaza European Hospital, which had housed displaced families as well as patients, was also evacuated.

An Israeli defence official said that although evacuation orders had been issued for the area where the European Gaza Hospital is located, staff and patients had been told they could stay.