Israeli warplanes struck dozens of targets in Gaza early on Friday after rockets were fired at Tel Aviv for the first time since the 2014 war between Israel and Hamas.
In the hours after the Israeli strikes, another nine rockets were fired from Gaza towards southern Israel, according to the Israeli military.
No fatalities were reported on either side but the escalation comes after weeks of tension on the Gaza border and at a politically sensitive moment in the middle of Israel’s election.
The incident began at around 9pm on Thursday when two rockets were fired from Gaza towards Tel Aviv, Israel’s second largest city.
Sirens wailed and municipal bomb shelters were opened for the first time since the 2014 war.
Although the rockets fell harmlessly in open areas, any effort to strike on Tel Aviv is considered a major escalation by Israel.
Israel said that Hamas, the Islamist militant group which controls Gaza, had fired the rockets.
However, Hamas denied it was responsible and promised to take action against those who fired them. “The rockets tonight are against the national consensus,” the Hamas interior ministry said.
Benjamin Netanyahu, Israel’s prime minister and defence minister, summoned Israel’s military and security leadership to the defence ministry.
Mr Netanyahu is trailing behind his centrist opponents in opinion polls ahead of the April 9 elections and was under intense political pressure from all sides to mount a significant retaliation.
In the early hours of Friday morning, Israeli warplanes struck around 100 Hamas targets inside Gaza, according to the Israeli military.
The Israel Defence Forces (IDF) said they attacked a rocket manufacturing site, a Hamas naval post, and a centre used to plan Hamas operations in the occupied West Bank. Palestinian media said that only 27 targets had been struck.
The Hamas health ministry said four people had been injured in the strikes including a man and a woman in Rafah, a city in Gaza near the Egyptian border.
A delegation of Egyptian security officials had been in Gaza working on efforts to mediate between Israel and Hamas after weeks of heightened tensions.
The Egyptians reportedly left Gaza immediately after the first rockets were fired, to avoid being caught up in an escalation between the two sides.
Israel’s military said that rocket fire continued on Friday morning and that nine projectiles were fired from Gaza into southern Israel.
Six of the rockets were intercepted by Israel’s Iron Dome missile defence system while another failed to clear the Gaza border, the IDF said.
Israel and Hamas have not fought a major war since 2014 but in the last year there have been periodic flare ups.
In each case, a ceasefire has been brokered by Egypt and the UN but civilians on both sides live in fear of another outbreak of all-out war.
The flare-up of Thursday and Friday drew a US statement of support for Israel. "Hamas and other terror orgs in Gaza continue to fail their people day after day & drag Gaza further & further down by constantly choosing violence," tweeted Jason Greenblatt, the White House’s Middle East envoy. "This method will never work. Ever!"
Tensions have been high for the past year along the Israel-Gaza frontier since Palestinians began violent protests near Israel’s border fence that have often drawn a lethal response from the Israeli military.
About 200 Palestinians have been killed in the demonstrations and about 60 more Palestinians have died in other incidents, including exchanges of fire across the border. Two Israeli soldiers have been killed by Palestinian fire.