Palestinian militants in the Gaza Strip have intensified a wave of rocket fire into southern Israel, striking towns and cities across the region.
At least 12 Palestinians, including a pregnant woman and her 14-month-old niece, have also been killed.
Israeli forces struck dozens of targets throughout Gaza, including militant sites that it said were concealed in homes or residential areas.
The army also moved armoured units toward the Gaza perimeter as the sides headed closer to all-out war.
Moshe Agadi, a 58-year-old Israeli father of four, was struck in the chest by shrapnel in a residential courtyard from one of the 450 rockets fired from Gaza in less than 24 hours.
Then a midday barrage hit Ashkelon again, wounding three people, including two seriously who were suffering from “multisystem trauma”.
The Israeli military has retaliated with some 260 airstrikes against militant targets in Gaza.
The Palestinian Health Ministry had previously said an Israeli strike on Saturday killed a pregnant woman, Falistin Abu Arar, 37, and her niece, Seba Abu Arar, in their east Gaza City home.
However, military spokesman Lt Col Jonathan Conricus said Sunday that a detailed review found that a Palestinian rocket had misfired and killed them.
He said the Palestinians were “trying to sell a story that isn’t true”. The conflicting accounts could not immediately be reconciled.
Hospital officials in Gaza confirmed the deaths of two men, ages 28 and 21.
Islamic Jihad media outlets said the two were militants. Their deaths raised to nine the number of Palestinians killed in the recent fighting.
The sudden outburst has broken a month-long lull as Egyptian mediators had been trying to negotiate a long-term cease-fire between the two sides, who have fought three wars and several other rounds of conflict over the past decade.
Conricus said Israel’s strikes hit a variety of “high-quality” militant sites, that included commanders’ homes in which militant activity was observed. He said he had no knowledge of civilians being harmed by Israeli fire.
The military spokesman said Israel was deploying an armored brigade along the Gaza front, with tanks ready for offensive missions as needed. The Israeli military has already struck rocket launchers, tunnel shafts, training sites, storage depots and warehouses of both the territory’s Hamas rulers and the smaller, Iranian-backed Islamic Jihad group.
Israeli Prime Minister Benjamin Netanyahu said Hamas was paying a “heavy price” for its rocket attacks against Israel and that it would be held accountable not only for its own militant actions but also for that of the Islamic Jihad, which operates under its jurisdiction in Gaza.
Sirens wailed along the border region overnight and throughout the day warning of incoming attacks. School was canceled in southern Israel and emergency protocol enacted. As the day progressed, rockets were being fired deeper into the Israeli heartland.
In Gaza, large explosions thundered across the blockaded enclave during the night as plumes of smoke rose into the air.
One of the airstrikes hit a six-story commercial and residential building that housed the office of Turkey’s official Anadolu news agency.
“We thought the Rimal neighborhood is safe, but it seems there is no safe place in Gaza,” said Nidal al-Dali, who lived in the building and lost his home.
Turkish Foreign Minister Mevlut Cavusoglu called it a “new example of Israel’s unrestrained aggression”.
The Israeli military says its Iron Dome defense system intercepted more than 150 of the projectiles from Gaza, but several still managed to slip through. A rocket scored a direct hit on a residential home in the border town of Sderot.