Three Israelis have been killed and two others injured after rockets fired from Gaza hit an apartment block in the south of the country, police have confirmed.
Dozens of rockets hit Israel overnight, with the fatalities occurring in the town of Kiryat Malahi, 15 miles north of Gaza, the BBC reported.
Hebrew language newspaper Ynet reported that two men and a woman, two seriously injured and two babies were taken to hospital with minor injures.
Volunteers clean blood stains from a children's room in an apartment in a building that was hit by a rocket fired from the Gaza Strip
The three were named on Thursday afternoon as Aharon Smadga, 49, Itzik Amsalem, 24, and Mirah Sharf, 26. All will be buried on Thursday evening.
The Times of Israel reported that Ms Sharf was pregnant when she was killed, and was visiting Israel from India for a memorial services for those who died in a terror attack on a rabbi's home in Mumbai in 2008.
The attacks came after Hamas military leader Ahmed Jabari was killed in a 'surgical' missile strike by the Israeli defence force on Wednesday.
A rocket launched by Palestinians makes its way from the northern Gaza Strip
Some 11 Palestinians have been reported killed in Israel's 'Operation Pillar Of Defence' with two young children among the dead.
Explosion and smoke rises following an Israeli air strike in the northern Gaza Strip
Meanwhile Hamas has said that Israel will "pay a high price" for the attack, while Izz ad-Din al-Qassam, the military wing of Hamas, posted a message on its Twitter profile warning that the strike had opened "the gates of hell."
Israeli Prime Minister Benjamin Netanyahu has threatened to expand its operation against Hamas to protect Israeli citizens, with the Israeli military tweeting it was prepared to send ground troops in if necessary.
An urgent UN Security Council meeting was called amid the escalating violence, with UN Secretary Ban Ki-moon and President Barack Obama urging a measured response.
The car in which Ahmed Jabari was travelling
The United States "strongly condemned" the rocket fire from Gaza into southern Israel and Obama reiterated Israel's right to self defense. However it urged Israel it "make every effort to avoid civilian casualties."
Ambassador Susan Rice told the UN Security Council the US "regretted" the death and of innocent Israeli and Palestinian civilians, according to Associated Press.
She added: "Hamas claims to have the best interest of the Palestinian people at heart, yet it continues to engage in violence that does nothing but set back the Palestinian cause."
A Palestinian relative carries a wounded girl into the treatment room of Shifa hospital following an Israeli airstrike
Jabari has long been a key target for the Israeli Defence Force, and topped Israel’s most-wanted list for his apparent involvement in a string of attacks against Israel, including co-ordinating the capture of soldier Gilad Shalit in 2006, who was held hostage in Gaza for more than five years.
Reuters reported Ismail Haniyeh, the prime minister of Hamas’s Gaza government, saying in a statement: “We call on our Arab brothers, and especially Egypt ... and the new Egyptian presidency, to suppress this barbaric campaign in defense of Gaza and its people."
“I call for an urgent Arab summit to confront the brutal aggression,” he added.
Benjamin Netanyahu, Israeli Prime Minister
Palestinian negotiator Saeb Erekat told Al Jazeera the assassination of Jabari is “a major escalation against our people in Gaza… We hold the Israeli government responsible."
Amnesty International Middle East and North Africa Deputy Director Ann Harrison called for restraint from all sides.
She said: “All sides have to step back from the brink in order to protect civilian lives.
“The Israeli military must not carry out further indiscriminate attacks, or attacks in densely-populated residential areas that will inevitably harm civilians.
“Palestinian armed groups in Gaza meanwhile must not fire indiscriminate rockets into Israel. The international community must put pressure on both sides to fully respect the laws of war and protect civilian lives and property.”
Egyptian President Mohammed Mursi has recalled the ambassador to Israel and summoned Israel’s ambassador in Cairo, calling for an "immediate halt to the attacks."
In the wake of the attack, the IDF launched a social media offensive, warning other Hamas leaders they too were targets, and live-tweeting attacks from both sides.