Palestinian militants in the Gaza Strip fired two rockets toward Tel Aviv late Thursday, the Israeli military said, marking a significant escalation that raised the likelihood of a harsh Israeli reprisal.
The army said early Friday that targets included an office complex in Gaza City, an underground complex that served as Hamas' main rocket-manufacturing site, and a center used for a Hamas drone program.
The Israeli military says it has begun attacking sites in the Gaza Strip in response to a rocket attack on Tel Aviv.
In Gaza, both rulers Hamas and Islamic Jihad, an allied group, issued statements denying any responsibility for the attack, which came just over three weeks ahead of Israel's April 9 election.
"Two civilians were injured in Gaza City while two others were hurt in the southern city of Rafah", Ashraf al-Qidra, a spokesman for Gaza's Health Ministry, said.
"We hold Hamas responsible for all attacks launched from the territory under its control, and urge the worldwide community to publicly recognize that this offensive came unprovoked and that Israel has the full right to do whatever is required to safeguard the security of its residents and citizens", Singer said.
The rocket barrage triggered air raid sirens throughout the city, Israel's densely populated commercial and cultural capital.
Israeli defense officials said after a preliminary investigation that the Gaza rockets that hit the Tel Aviv area were apparently fired by mistake. No interceptions were made by aerial defense systems and no damage or injuries were reported.
Tel Aviv's Iron Dome missile defense system was activated during the attack and intercepted at least one rocket.
The Qassam Brigades, the armed wing of the Hamas militant group that runs Gaza, has said it was not responsible. Israel and Egypt have maintained a crippling blockade on Gaza since Hamas took over the territory in 2007.
The rocket attack Thursday night caught the Israeli military off guard and marked the first time that Tel Aviv, some 80 kilometers north of Gaza, has been targeted since a 2014 war.
It's a first since Israel's 2014 campaign in Gaza.
He said that while "rogue factions" were behind recent Gaza "provocations", it "did not exempt Hamas" of responsibility.
Islamic Jihad, another Iranian-backed terror group in Gaza with a large rocket arsenal, also denied firing the rockets.
Israel's Education Minister and security cabinet member Naftali Bennett urged: "The time has come to defeat Hamas and eliminate its leaders, I am calling on the prime minister to convene the cabinet and to force the IDF to present a plan for the destruction of Hamas".