The Israel Defense Forces on Saturday afternoon launched a series of strikes on the Gaza Strip from both land and air, as around 200 rockets were fired toward Israel from the Palestinian enclave.
The army said dozens of the projectiles were intercepted by the Iron Dome missile defense system.
A woman, aged around 80, was in serious condition after being hit by shrapnel from a rocket in Kiryat Gat, about 20 kilometers (12 miles) northeast of the Gaza Strip. She was treated by medics at the scene and taken to hospital, where she was in stable condition.
A man was in a moderate condition after he was injured by shrapnel after a rocket attack on the coastal city of Ashkelon.
Shortly after 3 p.m. the army said fighter jets and tanks had struck 30 "terror targets" in the Strip belonging to the Hamas and Palestinian Islamic Jihad terror groups. The operations were ongoing.
The army said it targeted several Hamas compounds in Gaza City used for training and for weapons production. It said one of the sites was used by the organization's naval force.
It also struck several Islamic Jihad compounds throughout the Strip, and a number of rocket launchers and outposts near the border.
The strikes came after IDF Chief of Staff Aviv Kohavi held talks with Shin Bet chief Nadav Argaman, Southern Command chief Herzi Halevi and other top brass. Prime Minister Benjamin Netanyahu, who is also defense minister, was set to hold consultations at the IDF headquarters in Tel Aviv as well.
The strikes were in response to around 200 rockets launched at Israeli communities from the Strip since the morning, with thousands of Israelis forced into shelters throughout multiple towns and cities near Gaza, including in Rehovot, Ashkelon, Ashdod and Sderot.
And at 3 p.m. sirens sounded for the first time as far as Beit Shemesh, a city 20 kilometers (12 miles) west of Jerusalem.
The Iron Dome missile defense system intercepted dozens of projectiles.
A home in a community in the Eshkol Regional Council suffered a direct hit, without reported casualties, as the residents had run to a nearby shelter moments earlier once sirens were heard. Police were at the scene.
Also in Eshkol, a rocket fell inside a community but did not cause damage. Another rocket impacted on Route 4, a major highway, near Ashkelon. Sappers handled the rocket remains.
Magen David Adom said none were injured by the rocket barrages. However, a 15-year-old boy was lightly hurt running to a shelter, and two people suffered from shock.
In its initial response to the attacks in the morning, the IDF said the air force struck at least two rocket launchers in the Strip, and tanks fired at several posts belonging to the Hamas terror group, which rules Gaza.
The Hamas-run Gaza health ministry said a 22-year-old man was killed and four people were injured by the Israeli strikes. It did not say whether the casualties were people affiliated to any terror group. Channel 12 news reported that the dead man may have been a member of a rocket-launching squad that had fired at Israel, but there was no official confirmation.
No Gaza terror group immediately claimed responsibility for the rocket fire. However, Hamas in a statement said it was "prepared to respond to Israel's crimes" and vowed to stop it from "spilling the blood of our people." Gaza's second-largest terror group, Islamic Jihad, warned that "If Israel continues the aggression it will face surprises." And a spokesperson for the Popular Resistance Committees said "The resistance groups are breaking the formula that Israel tried to create, whereby it could attack without there being a response."
An unidentified Hamas source told the Haaretz newspaper that the group had "warned of escalation for the past two weeks due to the delay in carrying out the understandings of the ceasefire. In Israel they asked for calm and got it, and in the Strip we didn't get any improvement."
According to the Walla news site, IDF troops in the region were alert to possible attempts to snipe at or launch anti-tank missiles at forces near the border, as well as possible abduction attempts.
In light of the ongoing attacks, the IDF's Home Front Command issued instructions for residents in affected areas to remain near protected spaces. It also limited public gatherings to 300 people in enclosed spaces only and halted agricultural work. Many municipalities opened public shelters. Beaches and national parks in the south were closed, and sporting events canceled.
The instructions applied to communities in the border area near Gaza, the central Negev, Lachish region and southern Shfela plain.
The rocket attacks came a day after two soldiers were shot and injured while on patrol near the border in southern Gaza. One soldier was moderately wounded in the attack and a female soldier was lightly hurt, the IDF said.
In response to the shooting, an IDF aircraft attacked a nearby Hamas post, the army said. The Hamas-run Gaza health ministry said two people were killed in the strike and two others were wounded.
Hamas confirmed the two men killed in the airstrike were members of its military wing and pledged to respond to what it called "Israeli aggression."
The Hebrew-language Twitter account of the Hamas-affiliated Shehab news agency issued a threat to Israel Friday night: "We will respond to the crimes of the occupation and the killing of our people."
The Islamic Jihad also said it held Israel responsible for the deaths.
The incidents, which marked a serious escalation, came during weekly border protests in which several thousand Gazans gathered at five sites. Some of the demonstrators rioted, throwing rocks and makeshift explosive devices at soldiers, who responded with tear gas and occasional live fire.
A third Palestinian was killed during the border riots, the Gaza health ministry said, identifying him as Ra'ed Khalil Abu Tayyer, 19, adding that 40 protesters had been injured. The IDF said troops had identified several attempts to breach the fence. Overnight Friday, a fourth Palestinian died from injuries sustained during the riots, according to Hebrew media reports.
On Thursday, a Hamas delegation led by the group's Gaza chief Yahya Sinwar traveled to Cairo for talks with Egyptian officials on a truce with Israel, Hamas officials said.
That agreement has appeared to be under stress in recent days, with Palestinians launching arson balloons and rockets into Israel and Israeli warplanes striking Hamas targets.
Hamas has said the incendiary balloons were a message to Israel not to hold up the transfer of millions of dollars in Qatari aid funds to the cash-strapped Hamas government in Gaza.
Israel and Egypt have maintained a crippling blockade on Gaza since Hamas, which seeks to destroy Israel, seized control of the territory in 2007. Jerusalem says it is necessary to prevent terror groups from rearming and becoming an even greater menace.
The sides are bitter enemies and have fought three wars and engaged in numerous smaller flare-ups of violence.
Tensions have been rising in recent days amid allegations from Hamas that Israel has been delaying implementation of last month's ceasefire understandings.
Following heavy fighting in early April, Israel agreed to ease the blockade in exchange for a halt to rocket fire. This included expanding a fishing zone off Gaza's coast, increasing imports into Gaza and allowing the Gulf state of Qatar to deliver aid to cash-strapped Gaza.
Hamas has hoped that Egyptian mediators could further ease the blockade, which has ravaged Gaza's economy. For over a year, the Islamic group has orchestrated mass demonstrations each week along the Israeli frontier to draw attention to Gaza's plight.