Maen Rashid Areikat, Palestinian Liberation Organization's ambassador to the United States, stresses the need for a cease-fire agreement and responds to claims that Hamas is using Palestinian civilians as human shields. (Theresa Poulson/The Washington Post)

Maen Rashid Areikat, Palestinian Liberation Organization's ambassador to the United States, stresses the need for a cease-fire agreement and responds to claims that Hamas is using Palestinian civilians as human shields. (Theresa Poulson/The Washington Post)

Plans for a truce devolved into threats of a wider war Tuesday as the first significant attempt to end more than a week of round-the-clock fire between Israel and Hamas ended before it had even begun.

The unraveling of an Egyptian cease-fire proposal offered little immediate hope for a diplomatic solution to a conflict that has left at least 204 Palestinians in Gaza dead and that on Tuesday claimed its first Israeli fatality.

Israeli Prime Minister Benjamin Netanyahu gave the military authorization to use “full force” against militants in Gaza and vowed that Hamas and its allies would suffer for their decision not to halt their rocket fire into Israel.

“Hamas chose to continue fighting and will pay the price for that decision,” Netanyahu said in a televised address Tuesday evening. “When there is no cease-fire, our answer is fire.”

By early Wednesday morning, Israel had struck at least 25 targets inside Gaza, including the home of a senior Hamas leader, Mahmoud Al Zahar, according to Israeli news reports. Hamas militants fired at least 13 rockets into southern Israel, seven of which were intercepted by Israel’s Iron Dome air defense system, said Israel’s military in Twitter feeds. Several Palestinians were killed in the predawn hours of Wednesday, according to Palestinian health officials.

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Netanyahu was under pressure from his right flank late Tuesday to authorize a risky ground invasion of Gaza aimed at ending Hamas’s reign as the de facto power in the coastal strip. Reflecting tensions within his government, Netanyahu fired his deputy defense minister for publicly accusing the cabinet of not moving aggressively enough against Hamas.

The Islamist militant group also showed signs of internal strain, with its military wing vowing to escalate the conflict even as a top political leader said the group was considering Egypt’s cease-fire plan.

The proposal, offered late Monday night, called for Israel and Hamas to stop firing Tuesday without preconditions and then launch talks in Cairo within 48 hours.

Israel’s security cabinet approved the deal Monday morning, and Israel stopped its attacks on Gaza at 9 a.m. local time. But Hamas officials balked at the proposal, saying they had never been consulted. The rocket fire from Gaza continued unabated, and Israel resumed military operations in the territory at 3 p.m.

The failure of the initiative reflected the absence of a diplomatic player with both the clout and credibility to mediate the crisis. That role has traditionally been played by Egypt. But the country’s military-backed government is deeply hostile to Hamas, an Islamist militant offshoot of Egypt’s Muslim Brotherhood, which Cairo authorities consider a terrorist organization.

“There’s a common denominator between Israel and Egypt, and that’s Hamas,” said Itzhak Levanon, a former Israeli ambassador to Egypt. “Both really want to see Hamas weakened, not only militarily but also politically. There’s a convergence of interests.”

That convergence led Egypt to spring the cease-fire proposal without prior warning late Monday night, said senior Hamas leader Sami Abu Zuhri, who described the move as a trap.

View Graphic The Iron Dome defense

“We are holding in our hands a proposal we got off social media,” Zuhri said. “We refuse to be dealt with in such a way.”

Hamas has said it will only agree to a cease-fire with preconditions and has set forth a number of demands, including the reopening of Gaza’s border crossing with Egypt and the release of hundreds of prisoners swept into Israeli jails last month. Halting the rocket fire would eliminate much of the group’s leverage.

By not agreeing to the truce deal, Hamas has taken some of the international pressure off Israel while deepening its own isolation.

The United States has done little to push Israel toward ending its operations in Gaza, and on Tuesday, the White House made clear that the onus is on Hamas to end its fight.

“All eyes now turn to Hamas and the groups in the Palestinian territories firing rockets,” said White House press secretary Josh Earnest.

Israeli authorities believe that Hamas is far weaker than it was the past two times the two combatants engaged in major combat and are reluctant to give the group anything that could be perceived as a reward for its militancy. In both previous rounds — in the winter of 2008-09 and in late 2012 — Hamas proclaimed victory despite the fact that the vast majority of the deaths, damage and injuries occurred in Gaza.

That has also been true this time. An Israeli military intelligence official said Tuesday he believed that up to half of Hamas’s rocket stores had been destroyed in the past eight days and that Israel had done significant damage to the group’s

weapons-production facilities. The group’s financial picture, meanwhile, is bleak after Iran and other international backers withdrew their funding.

But Hamas and its allies are believed to still have thousands of rockets, including some that are capable of penetrating deep into Israeli territory. On Tuesday, an Israeli civilian in his 30s was killed by mortar fire near the Gaza border while delivering food to soldiers, marking the first Israeli death since the conflict began. At least 15 Israelis have been injured, police say. Israelis credit the Iron Dome missile defense system with keeping casualty numbers low.

The toll has been far greater among Palestinians, with about 1,500 injured in addition to the 204 who have been killed, according to the Gaza Health Ministry. After ending its short-lived unilateral cease-fire Tuesday afternoon, Israel struck dozens of targets in Gaza, including concealed rocket launchers, tunnels and a weapons-storage facility.

But there were indications that a much broader operation could be on the way, as residents of northern Gaza were advised late Tuesday to leave their homes and move to safer areas of the strip.

Israel has called up 40,000 reservists and massed three brigades on the border with Gaza in anticipation of a possible ground offensive that it has repeatedly threatened. A former Israeli ambassador to the United States, Michael Oren, said Tuesday that Hamas’s rejection of the Egyptian cease-fire meant that “Israel will have the legitimacy to go into Gaza and to pursue its goal with more force.”

Netanyahu has resisted such a move, reasoning that the costs would be too high. But he faces a challenge from more hawkish ministers who believe that Israel must do something to permanently change the dynamic in Gaza.

One such official, Deputy Defense Minister Danny Danon, was fired by Netanyahu on Tuesday night for publicly speaking out against the government. Danon later released a blistering statement accusing Netanyahu’s government of capitulating to Hamas amid “a defeatist atmosphere.”

Danon has repeatedly urged Netanyahu to take advantage of Hamas’s relative weakness and try to topple the organization.

Mkhaimar Abusada, a political scientist at Al-Azhar University in Gaza, said Hamas had indeed been substantially diminished in the past year, primarily because Egypt shut down the smuggling tunnels that had been a major source of revenue. But a ground invasion by Israeli forces, he said, would be a huge mistake. “This,” he said, “would be a catastrophe.”

Booth reported from Gaza City. Ruth Eglash in Jerusalem contributed to this report.