Israel is making plans for a potential major ground offensive in Gaza that would involve sending tens of thousands of troops into combat to clear and occupy large swaths of the enclave, an Israeli official and a second source familiar with the matter said.

Israel will take more territory in Gaza and fight until Hamas is wiped out if the Palestinian militant group keeps refusing to free remaining hostages, Israeli Defence Minister Israel Katz said on Tuesday.

Israel said it has targeted prominent members of Hamas in recent days, including the group’s new prime minister in a “precise strike” on where he was operating within Gaza’s Nasser Medical Complex.

Palestinian medics say Israeli strikes killed at least 23 people in the Gaza Strip overnight into Tuesday. Nasser Hospital said it received four additional bodies from two other strikes in addition to the family of five.

The United Nations is withdrawing about one-third of its international work force in Gaza, with the reduction coming after an Israeli tank shell hit a U.N. compound.

Israeli strikes across the Gaza Strip killed at least 23 Palestinians, local health officials said, as the Israeli military expanded evacuation orders.