Three Israelis have been killed in a rocket attack from Gaza against southern Israel, police officials said.
The attack struck an apartment building, a spokesman said, and is likely to produce a harsh response from Israel as it wages an offensive against militants in the Hamas-ruled Palestinian territory.
Israeli aircraft, tanks and naval gunboats pounded the Gaza Strip on Wednesday as Israel targeted the Islamic militants. The operation, launched in response to days of rocket fire from the Palestinian territory, kicked off with the assassination of Hamas's top military commander.
Israel's already strained relations with Egypt's new Islamist government frayed even further as Egypt recalled its ambassador in response to the Israeli military operation.
Days earlier, Israel was drawn into Syria's civil war for the first time, firing missiles into its northern neighbour for the first time in four decades after stray mortar fire landed in Israeli-occupied Syrian territory.
Waves of air strikes on more than 100 militant targets quickly followed the assassination of Hamas mastermind Ahmed Jabari. The air attacks continued steadily into the early hours today, targeting the armed group's training facilities and rocket launchers in Israel's most intense attack on the territory since its full-scale war there four years ago.
Ten Palestinians, including two young children and seven militants, were killed on the operation's first day, and more than 93 were wounded. Earlier, Israel targeted a motorcycle carrying a rocket squad, killing one militant and wounding two, a Palestinian health official said. The Israeli military had no immediate confirmation of this report.
Tank shells and naval gunfire backed up the air onslaught. Few in the territory's largest urban area, Gaza City, heeded the call for dawn prayers, and the only vehicles plying the streets were ambulances and media cars.
Schools have been ordered closed until the operation ends, and most of the territory's 1.6 million people are expected to hunker down close to home, venturing out only to buy food, fuel and other basic supplies.
Hamas announced a state of emergency in Gaza, evacuating all its security buildings and deploying its troops away from their locations. Dozens of rockets bombarded southern Israel after the operation began, the militants undeterred by the relentless air attacks. No serious casualties were reported as Israel declared a state of emergency in its south and instructed people to remain close to fortified areas.