The persistent escalation of hostilities came as Egyptian negotiators held in-person talks with the 2 sides, intensifying efforts at mediation.
Previous fighting between Israel and Gaza's Hamas rulers, such as a devastating 2014 war, was mostly restricted to the impoverished and blockaded Palestinian land and Israeli communities around the frontier. However, this round seems to be rippling farther and broader than anytime since the 2000 Palestinian intifada, or uprising.
Whenever some rocket strikes have reached the Tel Aviv area, Arab and Jewish mobs have rampaged through the streets, savagely beating people and torching cars. Flights have been canceled or redirected away from the nation's most important airport.
Since the rockets began Monday, Israel has toppled three high tech buildings it said housed Hamas facilities following warning civilians to flee.
Gaza's Health Ministry said the death toll has climbed to 87 Palestinians, including 18 children and eight women, with 530 people wounded. Islamic Jihad affirmed the deaths of seven militants, while Hamas has acknowledged 13 of its militants murdered, including a senior commander. Israel says the number of militants dead is much greater.
Seven people are killed in Israel. Among these were a soldier murdered by an anti-tank missile and a 6-year-old child hit in a rocket attack.
Many world leaders have condemned the violence and urged restraint, and a visit by Egyptian security officers was a significant development in international efforts to bring about a cease-fire; such attempts have been key to finish past rounds of fighting. The officials met first with Hamas leaders in Gaza before holding talks with the Israelis in Tel Aviv, two Egyptian intelligence officers said. They spoke on condition of anonymity because they weren't authorized to talk to the media.
Still, both Israel and Hamas seemed determined to press forward.
Even as word came of the mediators' existence, Gaza militants fired a volley of some 100 rockets nearly simultaneously, increasing air raid sirens around southern and central Israel.
There were no immediate reports of damage or casualties -- but the barrage seemed aimed at demonstrating Hamas' arsenal was still full even after three nights of airstrikes and the killing Wednesday of many Hamas leaders involved with the rocket program.
"The best way to bomb Tel Aviv, Dimona and Jerusalem is easier for us than drinking water," a spokesman for Hamas' military wing announced in a video message. Dimona is the website of Israel's nuclear reactor.
In another sign fighting could increase further, Israel's defense ministry accepted the mobilization of 9,000 longer reservist troops, and Israel's army spokesman said forces were massing on the border with the Gaza Strip.
The army's main spokesman, Brig. Gen. Hidai Zilberman, stated forces were"preparing the choice of a ground maneuver." He told Israeli public tv station Kan that tanks, armored personnel carriers and artillery were being readied"for this option for mobilization at any given time"
However, the degree of forces wasn't believed to be powerful enough yet for a possible ground invasion.
Israeli Prime Minister Benjamin Netanyahu visited batteries of this Iron Dome missile defense system, that the army says has intercepted 90 percent of the 1,200 rockets that have reached Israel from Gaza so far.
"It takes more time, however... we will achieve our aim -- to restore peace to the State of Israel," he said.
The previous day, Israeli TV reported Netanyahu's Security Cabinet authorized a portion of the offensive that the military says has hit 600 targets in Gaza.
In Gaza, a pall was cast over Eid al-Fitr, the holiday at the conclusion of Ramadan's month of daily fasting. It's generally a festive time when households search for new clothes and gather for big feasts.
Instead, Hamas urged the faithful to mark communal Eid prayers in their houses or the closest mosques rather than out in the open, as is conventional.
Hassan Abu Shaaban tried to lighten the mood by passing out candies to passers-by after prayers, but acknowledged"there is not any atmosphere for Eid in any way."
"It is all airstrikes, destruction and devastation," he explained. "May God help everybody."
At Gaza's southern town of Khan Younis, dozens of mourners marched through the streets carrying the bodies of an 11-year-old and a 13-year-old killed when an Israeli airstrike hit close to their residence Wednesday.
Israel diverted some incoming flights in Ben Gurion International Airport, near the city, to the Ramon airfield from the country's far southwest, the Transportation Ministry said. Several flights also have been pinpointed.
Hamas said it fired its most powerful rocket, the Ayyash, toward Ramon, 180 kilometers (110 miles) from Gaza. Still, flights were temporarily suspended at the airport, with several airplanes left circling before landings and takeoffs were resumed, based on monitoring websites.
"We are dealing, sitting at home, hoping it'll be OK," said Motti Haim, a resident of the central city of Beer Yaakov and dad of two kids. "It's not simple running to the shelter. It's not easy with the kids."
U.S. President Joe Biden called Netanyahu to support Israel's right to defend itself, and also Secretary of State Antony Blinken said he was sending a senior diplomat into the region.
The current eruption of violence began a month ago in Jerusalem, in which heavy-handed Israeli police tactics during Ramadan and the threatened eviction of dozens of families by Jewish settlers triggered protests and clashes with authorities. A focal point of clashes between Palestinians and Israeli authorities was Jerusalem's Al-Aqsa Mosque, built on a hilltop compound that's respected by Jews and Muslims.
Israel regards Jerusalem in its entirety because its funding, while the Palestinians want east Jerusalem to be the capital of their future state.
The recent fighting has also set off violent clashes between Arabs and Jews in Israel, in scenes hidden in more than two decades. Netanyahu warned that he had been ready to use an"iron fist if needed" to calm the violence.
Ugly confrontations erupted again late Wednesday. Jewish and Arab mobs battled at the central town of Lod, the epicenter of these troubles, despite a state of crisis and nighttime curfew. In nearby Bat Yam, Jewish nationalists hauled an Arab driver from his car and beat him till he was motionless.
Israeli authorities said two people were shot and injured in Lod and an Israeli Jew had been stabbed. An Arab citizen has been stabbed and seriously hurt in Jerusalem's central Mahane Yehuda marketplace.
From the occupied West Bank, the Israeli army said it intervened in a Palestinian shooting attack that wounded two people. The Palestinian Health Ministry reported the suspected gunman was killed.
Still unclear is how the fighting in Gaza will influence Netanyahu's political potential. He neglected to create a government coalition after inconclusive parliamentary elections in March, and now his political competitors have three months to attempt to form one.
They have courted a small Islamist Arab party, but the battling could hamper these efforts.
Krauss reported from Jerusalem. Associated Press writers Samy Magdy in Cairo, Isabel DeBre in Dubai, United Arab Emirates, Karin Laub from the West Bank and Ashraf Sweilam in al-Arish, Egypt, led.