Tension and fear rose after militants in the Gaza Strip fired more than 90 rockets into Israel, the army revealed prompting air strikes and tank fire on the Palestinian territory.
Sirens went off as people rushed to shelters in southern Israel. There are no reports of casualties there, but one Palestinian has been been killed.
Four Palestinians, including two Hamas militants, were killed on Friday after an attack injured two Israeli soldiers.
The flare-up followed a lull in the run-up to Israeli elections in April.
It marks yet another increase in hostilities despite attempts by Egypt and the United Nations to broker a longer-term truce.
An 80-year-old woman was seriously injured on Saturday from the barrage of over 150 rockets which came into Israel from the Gaza Strip at the hands of Hamas.
A house was hit by one of the rockets. The house is located in Hof Ashkelon Regional Council in Southern Israel and no injuries were reported.
Iron Dome batteries intercepted dozens of rockets fired at Ashkelon and the Gaza border communities, according to the IDF Spokesperson’s Unit.