JERUSALEM -- A ceasefire proposed by Egypt to end a week of fighting between Israel and Islamist militants in the Gaza Strip failed to take hold early Tuesday as more rockets were fired into Israel and Prime Minister Benjamin Netanyahu warned that an Israeli offensive in Gaza could be expanded.
The army said that about 35 rockets had been fired at Israel as the armed wing of Hamas rejected the ceasefire, saying the battle with Israel would "increase in ferocity and intensity."
Musa Abu Marzuk, a top Hamas official who was in Cairo, said the movement, which is demanding an easing of border restrictions imposed by Egypt and Israel on Gaza, had made no fincal decision on the proposal.
Earlier, the Israeli security cabinet had approved the ceasefire, which was to provide for a 12-hour de-escalation period from Tuesday morning. Netanyahu said that Israel had agreed to the truce plan to provide an opportunity "to demilitarize the Gaza Strip of misssiles, rockets and tunnels by diplomatic means."
"If Hamas won't accept the ceasefire proposal, and that's the way it looks now, Israel will have full international legitimacy to broaden the military operation in order to restore the required calm," he said.
According to the Egyptian proposal, a ceasefire would take effect within 12 hours from its "unconditional acceptance" by the sides on Tuesday morning.
That would be followed by the opening of border crossings to Gaza and indirect negotiations in Cairo within 48 hours, the Egyptian Foreign Ministry said.
The proposal came ahead of a planned visit to Egypt on Tuesday by Secretary of State John Kerry.
At a Ramadan dinner at the White House, President Barack Obama said the United States was encouraged by the Egyptian proposal. But while he called the deaths of Palestinian civilians a tragedy, he gave no indication that the U.S. was pressing Israel to end the air strikes.
Weve been very clear that Israel has the right to defend itself against what I consider inexcusable attacks from Hamas, he said.
Hamas officials had no immediate response, but Ismail Haniyeh, a top Hamas leader in Gaza, said in a broadcast speech that there had been diplomatic movement, and that his group was seeking an end to border closures imposed by Israel and Egypt on the coastal enclave.
Haniyeh said that restoring calm was not the purpose of any agreement because we want this aggression to stop, he said. The problem is the reality of Gaza, the siege, the starving, the bombing. . . . The siege must stop and the people of Gaza need to live in dignity.
Hamas officials had insisted that they would agree to a cease-fire only if border closures were lifted and former prisoners rearrested by Israel in a crackdown on Hamas in the West Bank last month would be freed. The men were detained after the abduction and killing of three Israeli teenagers in the West Bank, which Israel blamed on Hamas.
Israeli Prime Minister Benjamin Netanyahu has said that the goals of the Israeli campaign were to deliver a heavy blow to Hamas while halting rocket attacks from Gaza for an extended period of time.
A similar truce was brokered by Egypt in 2012, but it gradually unraveled as rocket firings and Israeli airstrikes on Gaza resumed, escalating last month after the kidnapping of the Israeli teens and leading to the most recent round of cross-border fighting.
With Palestinians counting at least 185 dead and more than 1,300 wounded in seven days of fierce Israeli bombardments from land, sea and air, United Nations officials accused the Israeli military on Monday of failing to take adequate measures to prevent civilian casualties.
The dead in Mondays barrage included a 4-year-old girl who was reported killed along with two other people in a strike on the family home of a commander in the Islamic Jihad group in the southern Gaza Strip town of Rafah.
In Israel, two sisters, ages 10 and 13, were wounded, one seriously, when a rocket slammed into a Bedouin encampment in the southern Negev region.
Israeli strikes on scores of family homes of suspected militants in Gaza have led to multiple deaths of relatives and neighbors.
In the deadliest such attack, a house was bombed on Saturday in Gaza City, killing 18 people, including six children and three women, one of them pregnant, and wounding 16 others, according to the U.N. One of the wounded was Tayseer al Batsh, the Gaza police chief, who was apparently the intended target.
The U.N. Office for the Coordination of Humanitarian Affairs said in a report Sunday that 80 percent of those killed in the Israeli bombardments were civilians, and that the Israeli strikes had destroyed or severely damaged 940 homes, displacing 5,600 people.
Another 17,000 people from the northern Gaza Strip left their homes and sought shelter in 20 U.N.-run schools after the Israeli army ordered them to evacuate in advance of what the military said would be stepped-up airstrikes.
At a news conference Monday in Gaza, Pierre Krahenbuhl, the commissioner general of the United Nations Relief and Works Agency, which provides aid to Palestinian refugees, called on Israel to end attacks against or endangering civilians and civilian infrastructure, which are contrary to international humanitarian law.
The Israeli Foreign Ministry accused Hamas of committing war crimes by indiscriminately firing rockets at Israeli cities and storing arms in residential areas of Gaza. Hamass actions are in clear violation of the most fundamental principles of the laws of armed conflict, the ministry said.
Introducing a new element to the conflict, Hamas on Monday sent a drone into Israeli airspace. It was shot down with a Patriot surface-to-air missile off the coast near the southern Israeli city of Ashdod, the army said.
Hamas said it had launched three unmanned aerial vehicles into Israel, one of which reached the Israeli Defense Ministry headquarters in Tel Aviv, but Israeli military officials said only one aircraft was spotted and downed.
In the West Bank, Israeli troops shot and killed a Palestinian near Hebron. The army said soldiers opened fire at masked youths who threw stones and a Molotov cocktail at passing cars. The incident was under investigation by the military police, a spokesman said.