The U.S. insisted to Israel this week that it come up with clear plans to minimize civilian harm in any military operation in southern Gaza, a senior U.S. official said on Friday, as the Israeli military resumed bombardment of the enclave after a week-long truce collapsed.

Friday's bombing was most intense in the southern areas of Khan Younis and Rafah, however, medics and witnesses said. Hundreds of thousands of Gazans have been sheltering there because of fighting in the north. Houses in central and northern areas were also hit.

By the evening, Gaza health officials said Israeli air strikes had killed 184 people, wounded at least 589 others and hit more than 20 houses.

The bombings in the south occurred only hours after U.S. Secretary of State Antony Blinken told Israeli Prime Minister Benjamin Netanyahu during a visit to Jerusalem that Israel's operations in the area not repeat the massive loss of civilian life and displacement seen during its northern offensive.

Israel's government agreed that any operation in the south should not look like it did in the north and its military will designate areas where civilians will not be harmed, the senior U.S. official said as Blinken wrapped up a trip to the region.

However, Netanyahu and his government did not give clear assurances on avoiding civilian harm, and the official said the issue will continue to be discussed.

The official added that the U.S. expects there will be no full-scale assault on Khan Younis and Rafah as there was on Gaza City.

Washington has urged Israel to narrow the zone of combat and clarify where Palestinian civilians can seek safety in southern Gaza, officials have said.

The official, speaking on condition of anonymity on Friday, said during the current offensive entire neighborhoods in southern Gaza should be designated as zones that are safe for civilians, though some may still have to leave their homes if they are in areas where Hamas fighters are deeply embedded.

Israel has sworn to annihilate Hamas in response to the Oct. 7 rampage by the militant group, when Israel says gunmen killed 1,200 people and took 240 hostages. Hamas, sworn to Israel's destruction, has ruled Gaza since 2007.

In addition to those who planned the Oct. 7 attacks, Israel was looking to eliminate Hamas' battalion-level leadership, said the official.

Israel's assault has laid waste to much of Gaza. Palestinian health authorities deemed reliable by the United Nations say more than 15,000 Gazans have been confirmed killed and thousands more are missing and feared buried under rubble.

Asked at Dubai airport before leaving the region about the collapse of the truce and Israel's conduct on Friday, Blinken signaled Washington would continue dialogue with Israel.

"I saw the plans that Israel has, in a multiplicity of ways, to do everything possible to protect civilians, including making sure that they have the information they need and there are ways to accommodate them. And this is going to be very important going forward. It’s something we’re going to be looking at very closely," Blinken said.