The aerial bombardment set off earth-shaking thuds and fireballs in the dark sky and were met with screeches of Palestinian rocket fire launched from the outskirts of Gaza City towards southern Israel.
The airstrikes marked an escalation of two days of reciprocal attacks between the Palestinian militant Hamas group ensconced in the coastal enclave and the Israeli military, which killed a top Islamist leader on Wednesday.
Israel’s military said that in the space of an hour it had targeted approximately 70 underground launching sites for medium-range rockets.
“The sites that have been targeted were positively identified by precise intelligence collected over the course of months.” it said in a statement.
Residents said the military assault also destroyed an electricity generator that fed the house of Hamas’s prime minister in Gaza, Ismail Haniyeh. It was unclear whether he was at home at the time.
Israeli aircraft also bombed a police station in central Gaza and tunnels on Gaza’s border with Egypt through which basic civilian goods and arms destined for militant groups pass into the Strip, which is under a tight blockade by Israel and Egypt.
Israel will take “whatever action is necessary” to defend its citizens from Palestinian rocket attacks, Prime Minister Benjamin Netanyahu said on Thursday.
“Our army will expand its operations to protect Israel … more than 50 rockets landed in Israel during past 50 hours,” Netanyahu told reporters.
But a spokesman from Hamas, which held a press conference also on Thursday, condemned Israel for “trying to exploit the war on Gaza for political purposes.”
“Israel has used every weapon to attack civilians in Gaza,” he told reporters adding: “Our battle with Israel is open-ended, progressive and escalating.
‘We will not be exposed to further tricks by the occupation. We consider talk of a truce at this time an attempt to provide more cover for the continuation of the escalation on Gaza.
‘Talk of a truce is another attempt by the occupation at deception,’ he said, adding that ‘the enemy started an open war on our people and our resistance in Gaza,” he added
Meanwhile, Hamas and Islamic Jihad, another armed party in Gaza, launched two missiles against Tel Aviv -- the first time Israel’s commercial capital has come under such attack since the 1991 Gulf War. No injuries or damage was reported.
Earlier, a Hamas rocket killed three Israelis north of the Gaza Strip, drawing the first blood from Israel as the Palestinian death toll rose to 19, four of them children.
Israeli warplanes bombed targets in and around Gaza city for a second day, shaking tall buildings. In a sign of possible escalation, the armed forces spokesman said the military had received the green light to call in up to 30,000 reserve troops.
Israeli Defense Minister Ehud Barak said Palestinian militants would pay a price for firing the missiles.
At about the same time, Israeli aircraft conducted a wave of night raids on targets throughout the enclave, unleashing more than 25 strikes in swift succession.
An electricity generator supplying the home of Hamas prime minister Ismail Haniyeh by the Gaza shore was hit by an Israeli missile.
The conflict, launched by Israel with the killing of Hamas’s military chief, pours oil on the fire of a Middle East already ablaze with two years of revolution and an out-of-control civil war in Syria.
Egypt’s new Islamist President Mohamed Mursi, viewed by Hamas as a protector, led a chorus of denunciation of the Israeli strikes by Palestinian allies.
Mursi’s prime minister, Hisham Kandil, will visit Gaza on Friday with other Egyptian officials in a show of support for the enclave, an Egyptian cabinet official said. Israel promised that the delegation would come to no harm.
Israel says its attack is in response to escalating missile strikes from Gaza. Israel’s bombing has not yet reached the saturation level seen before it last invaded Gaza in 2008, but Israeli officials have said a ground assault is still an option.
Israeli police said three Israelis died when a rocket hit a four-story building in the town of Kiryat Malachi, 25 km (15 miles) north of Gaza, the first Israeli fatalities of the latest conflict to hit the coastal region.
The Gaza offensive began on Wednesday when a precision Israeli air strike killed Hamas military mastermind Ahmed Al-Jaabari. Israel then began shelling the enclave from land, air and sea.
At Jaabari’s funeral on Thursday, supporters fired guns in the air celebrating news of the Israeli deaths, to chants for Jaabari of “You have won.”