The IDF struck dozens of targets in Gaza from the air after more than 200 rockets were unleashed towards southern Israel in a coordinated attack on Monday afternoon.
Many Israeli homes and businesses were damaged by the rockets, with multiple images of damaged buildings, burst piping and raging fires shared on social media by users in towns close to the Gaza border.
There were no reports of Israeli fatalities in the hours following the attack, but an 19-year-old man was reported to be in a critical condition after the bus he was travelling in was hit.
The United Hatzalah medical response charity said its volunteers were treating many people in Sderot and the surrounding area for injuries and shock.
Sirens sounded across cities and towns in the region – including Be’er Sheva, which is home to some 200,000 people.
The rockets were launched from locations around Gaza almost simultaneously, testing the capabilities of Israel's Iron Dome missile defence shield.
As many as 60 of the incoming rockets had been intercepted, the IDF said.
In response, the Israeli air force launched strikes on at least 70 locations within Gaza, targeting "compounds, observation posts and rocket-launching squads", as well as tunnels beneath the land border with Israel, the IDF said.
Three Palestinian men were killed in the strikes, the Gaza Health Ministry and Palestinian media said.
#BREAKING: 100 rockets & morters launched from Gaza towards Israel in less then 40 minutes (video: Eliran Hajbi) pic.twitter.com/cJJH2vndM5
— Amichai Stein (@AmichaiStein1) November 12, 2018
There was no immediate information on the unnamed passenger travelling on the bus hit by a rocket near the kibbutz of Kfar Aza.
He was taken to the Soroka University Medical Centre in Beersheba.
Photographs from the scene showed firefighters tackling a raging blaze on the vehicle, which was reduced to a charred shell.
Prime Minister Benjamin Netanyahu, who had returned to Israel early from Armistice Day commemorations in Paris to respond to violence in Gaza earlier in the day, was meeting senior IDF generals on Monday evening.