Israeli strikes killed at least 40 Palestinians in the Gaza Strip on Friday, local health authorities said, most of them in Gaza City where many residents are staying put despite Israeli evacuation orders because they have nowhere safe to go.

Israel has stated its intention to take full control of the ruined city, where about a million people are sheltering, as part of its plan to wipe out Hamas, and has been intensifying its attacks, residents said.

Medical sources said 14 civilians were killed in a single strike on a house in the Al-Tuwam area, in the north of the city.

Several deadly strikes hit targets in the south of the territory, where some of those fleeing the bombardment of Gaza City have been heading.

Amjad Al-Shawa, head of the Palestinian NGOs Network, which liaises with the United Nations and international aid groups, told Reuters an estimated 10 percent of people in Gaza City had left since Israel announced its plan to take control of it a month ago.

The Israeli army said it had started expanding an area of the southern Gaza Strip it calls "Crossing 147" in order to increase the volume of aid entering a designated humanitarian zone. This was in preparation to receive the population leaving the northern area, it said.

The United Nations and many foreign governments have condemned the Gaza City evacuation order, called for a ceasefire, and sharply criticized conditions in the humanitarian zone.

(With input from Reuters)