Israel stepped up its bombardment of Gaza early Friday as tanks and artillery joined aerial attacks, an escalation that intensified fears of an all-out invasion.
Days of fighting between Israel and Hamas — the militant group that governs the Gaza Strip — has killed more than 100 Palestinians, including 31 children.
Israel said it carried out a 40-minute, pre-dawn barrage of 160 strikes aimed at destroying a vast network of tunnels used by Hamas, which is classified as a terrorist organization by Israel and the United States.
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Hamas continued firing rockets into Israel. It has launched 1,800 missiles this week, a barrage that has killed eight Israelis including one child, wounded hundreds of others and sent people fleeing into bomb shelters in Tel Aviv and other cities.
As ground forces joined Israel's intensifying response, it called up 9,000 reservists and amassed troops along its border with the tiny, impoverished enclave home to 2 million Palestinians.
It has been in "various stages of preparing ground operations" this week, according to a military spokesman.
There was confusion late Thursday after the Israeli military announced "ground troops" were attacking the area and media reports suggested Israeli soldiers had entered Gaza itself. It later clarified that this wasn't the case, but the incident highlighted the level of concern internationally that such a development — evoking the weekslong 2014 Gaza War — may be imminent.
Meanwhile, a fourth night of violent unrest flared in mixed ethnicity towns across Israel.
Overnight five Israeli police officers were injured in clashes and 750 people were arrested, according to the country's police.
The violence has seen rival Arab and Jewish mobs carrying out beatings and torching cars in an explosion of communal unrest that led its president, Reuven Rivlin, to warn against a "senseless civil war."
In Lod, a city near Tel Aviv that has seen some of the worst clashes, a synagogue was badly damaged after "rioters" set its door and a nearby palm tree on fire, according to a police spokeswoman.
As the tensions and clashes that first flared weeks ago in Jerusalem continued to sweep across Israel in a wave of fury, the conflict in Gaza escalated further.
Palestinian civilians say there is no escape from the violence in this densely populated territory, which is blockaded to the north and east by Israel and the south by Egypt.
At least 119 people, including 31 children, have been killed and some 830 injured, according to the Palestinian Ministry of Health. Eight Israelis including one IDF soldier have been killed by Hamas missiles, officials there said.
People living along Gaza's northern and eastern borders sought refuge on Friday in temporary shelters in central Gaza City, The Associated Press reported.
They arrived in pickup trucks, on donkeys and by foot at schools run by the United Nations, hauling pillows and pans, blankets and bread. Men lugged large plastic bags and women carried infants on their shoulders, cramming into classrooms.
One mother who fled to a downtown school with her children said "nothing remains for us" back home in the northern town of Beit Lahiya, the AP said. Her son, Othman, said he had felt the family's house "shake up and down," adding that "everyone was running."
Fatou Bensouda, a prosecutor at the International Criminal Court, said in an interview with Reuters on Friday that she was looking at the conflict "very seriously" and warned it could be folded into an ongoing ICC investigation into the 2014 Gaza War.
It is examining whether Israeli forces committed war crimes when they swept into the heavily urbanized enclave.
It is also probing whether Hamas and other armed factions carried out intentional attacks on civilians with rocket fire into Israel, as well as torture and killings of Palestinians by Palestinian security services.
Israel rejects membership of the court and accuses Bensouda's office of anti-Semitic bias.
President Joe Biden called for a de-escalation of the violence Thursday and said he expected to have more talks with leaders in the region.
The rocket attacks and airstrikes being exchanged by Israel and Hamas followed weeks of unrest in Jerusalem that saw clashes between Israeli police, Palestinian worshippers and nationalist Israelis. Another thread of disquiet had been the plans to evict Palestinian families from land claimed by Jewish settlers in East Jerusalem.
Hamas fired rockets toward Jerusalem on Monday after days of clashes at the holy city's Al-Aqsa mosque compound and Israel responded with attacks on Gaza.
"We're hunting terrorists," Lt. Col. Johnathan Conricus, an Israeli military spokesman, told a briefing Friday.
"We try to focus our firing and minimize civilian casualties. It's a complex and challenging operation," he said, adding that the military has mapped "sensitive targets" such as hospitals. "We try not to hit those," he added, but "sometimes Hamas uses these facilities on purpose."
At least one top Hamas commander was among those killed by the airstrikes, according to the group's military wing.
Conricus said Israel had killed at least 30 "terrorists."