A new front opened in the military showdown between the Israeli Army and Palestinian militants in Gaza on Wednesday as a wave of mob violence between Jews and Arabs spread across several Israeli cities, leading to riots and attacks in the streets as rockets and missiles streaked across the sky.

Israel said it assassinated 10 senior militants and continued to pound both military and residential areas across the Gaza Strip with airstrikes, while Hamas, the Islamist group that rules Gaza, and its allies continued to fire rockets into civilian areas across central and southern Israel.

More than 1,000 rockets had been fired from Gaza by Wednesday night, most of them intercepted by an antimissile defense system, the Israeli military said.

More than 67 Palestinians, including 16 children, have died since the start of the conflict on Monday, Palestinian health officials said. The rockets fired by Hamas and its Islamist ally, Islamic Jihad, killed at least six Israeli civilians, including a 5-year-old boy and one soldier.

The fighting showed no signs of letting up. An Israeli military official said Wednesday that three infantry brigades were “preparing for a worst-case scenario,” confirming that a ground invasion could follow the bombardment from the air.

But the most unexpected developments played out on the streets of Israeli cities and towns, as rival Jewish and Arab mobs attacked people, cars, shops, offices and hotels.

One of the most chilling incidents was in Bat Yam, a seaside suburb south of Tel Aviv, where dozens of Jewish extremists took turns beating and kicking a man presumed to be an Arab, even as his body lay motionless on the ground. A video of the attack was broadcast on Israeli television.

Israeli officials said they had “locked down” the city of Lod in central Israel, the first time such an action has been taken in decades, and arrested 280 people accused of rioting across the country.

Prime Minister Benjamin Netanyahu described the violence as “anarchy” and convened an emergency cabinet meeting that lasted into the early hours of Thursday to “give more powers to the police” and enforce curfews “as needed.”

The sudden turn of events, which in less than two full days has escalated from a localized dispute in Jerusalem to full-scale aerial war over Gaza to widespread civil unrest, shocked Israelis and Palestinians alike, and left some of the country’s most experienced leaders fearing that the decades-old Israel-Palestinian conflict was heading into new territory.

For years, leaders warned that a failure to resolve the Israeli-Palestinian conflict might eventually lead to fighting within the state of Israel itself, said Tzipi Livni, a veteran former cabinet minister and former chief negotiator in peace talks with the Palestinians.

“And this is exactly what is happening now,” she said. “What was maybe under the surface has now exploded, and created a combination that is really horrific.”