Fears of war as violence escalates between Palestinian militants in the Gaza Strip and Israeli military
Israel said, more than 1,000 rockets fired by Palestinian militants over 38 hours, most at Tel Aviv.
Destroying two tower blocks in Gaza, Israel has carried out hundreds of air strikes, on Tuesday and Wednesday. At least 53 Palestinians and 6 Israelis killed since Monday. That includes at least 14 Palestinian children.
UN Secretary General, António Guterres said he was "gravely concerned" by the growing violence.
An Israeli civilian was killed, when a missile, fired from the northern Gaza Strip, struck a jeep on the border. Three other people were injured.
The Israeli casualty also reportedly include a 52-year-old father and his 16-year-old daughter who died in the city of Lod near Tel Aviv when a rocket hit their car.
In Gaza, five members of one family were killed in an Israeli air strike. Streets are full of debris where buildings have collapsed and cars have been left burned.
Israeli Arabs have staged violent protests in some Israeli towns. Lod close by Tel Aviv has been put under a state of emergency.
PM Benjamin Netanyahu said the government would use all its power to protect Israel from enemies on the outside and rioters on the inside.
The fighting follows weeks of rising tension stoked by brutal confrontations between Israeli police and Palestinian protesters culminating in clashes at a site in Jerusalem that is holy to both Muslims and Jews.
Israel's military says the fighting is the most critical since the conflict in Gaza in 2014.
Of the, mortar shells and 1,050 rockets that have now been fired from the Palestinian territory 850 landed in Israel, and 200 failed to clear the border and landed back in Gaza, the Israeli squad said.
Video footage from the city showed rockets passing through the night sky, some of them exploding as they were hit by Israeli interceptor missiles.
Loud booms and air-raid sirens were heard across targeted cities, which included Tel Aviv, Ashkelon, Modiin and Beersheba, as Palestinian militants tried to overwhelm missile defences.
The rocket fire surged after the two huge residential tower blocks were brought down in Gaza. Israel said it was targeting rocket launch sites, homes and offices, high-rise building blocks used by Hamas, the militant group that rules Gaza.
Hamas said it was enraged by "the enemy's targeting of residential towers".