GAZA CITY: Militants defied a major Israeli bombing campaign across Gaza on Thursday, firing off volleys of rockets which killed three Israelis and sparked panic in Tel Aviv.

As Palestinian deaths from relentless air strikes on Gaza mounted, Defence Minister Ehud Barak gave the go-ahead for 30,000 reservists to be called up and the military said it was “in the process of expanding the campaign.”

Egypt, meanwhile, announced that Prime Minister Hisham Qandil would visit Gaza on Friday to express his country's solidarity with the Hamas-ruled strip, as Washington urged Cairo to use its influence to try to halt the violence.

But Gaza's ruling Hamas movement remained defiant, ruling out any talk of a truce even as Prime Minister Benjamin Netanyahu warned he was ready to “significantly expand” the campaign against the territory.

“In the past 24 hours, Israel has made it clear that it will not tolerate rocket and missile attacks on its civilians. I hope that Hamas and the other terror organisations in Gaza got the message,” he said, as Gaza medics reported 15 Palestinians killed in two days of air raids.

“If not, Israel is prepared to take whatever action is necessary to defend our people.”

Soon after he spoke, a rocket hit the sea just south of Tel Aviv, an AFP correspondent at the scene said, the farthest that a rocket from Gaza had ever landed inside Israel.

The attack sparked panic in Tel Aviv, with television images showing people lying on the ground outside the defence ministry, their hands over their heads as sirens wailed.

In a televised news conference shortly after the sirens sounded, the military's official spokesman said that no rocket had “hit the ground.”Israeli news networks said it was the first time rockets had been fired at the city since the 1991 Gulf War, when it was hit by Iraqi Scud missiles.

The armed wing of the radical Islamic Jihad quickly claimed it had fired an Iranian-made Fajr 5 rocket at the sprawling coastal city in central Israel.

The army's official spokesman warned that the military was expanding its campaign.

“The defence minister approved a few minutes ago, based on the army's request, the recruitment of another 30,000 soldiers. We will determine how many of them will be called in,” Brigadier General Yoav Mordechai told Channel 2 television.

“All options are on the table.” Hamas spokesman Sami Abu Zuhri insisted the Islamist movement was not interested by talk of a truce.

“We consider talk of a truce at this time an attempt to provide more cover for the continuation of the escalation,” he told a news conference.

Israel's biggest military campaign against Gaza in nearly four years began on Wednesday with the targeted killing of top Hamas commander Ahmed Jaabari, triggering a major flare-up in and around the tiny enclave which is home to 1.6 million Palestinians.

The violence, which erupted as Israel heads towards a January general election, sparked expressions of deep concern internationally and prompted an emergency meeting of the UN Security Council.

Since the start of Operation Pillar of Defence, the military said it had carried out more than 150 air strikes as armed groups fired more than 200 rockets at southern Israel.

So far, 15 people have been killed in Gaza, among them seven militants and three children, a woman and two elderly men, and 150 people have been injured in scores of Israeli strikes, medics and health ministry officials said.

And in the southern Israeli town of Kiryat Malachi, police said two men and a woman were killed when a rocket hit their home, and that another 19 people had been injured in various areas, among them three soldiers.

The Israeli operation prompted an outpouring of anger across the Arab and Muslim world, with Tehran accusing the Jewish state of “organised terrorism” and Qatar's premier saying the strikes “must not pass unpunished.”

Egypt's Islamist administration, which has close ties with Hamas, immediately recalled its ambassador in protest, but in a surprise development, announced that Qandil would would visit Gaza with a number of ministers on Friday.

US deputy State Department spokesman Mark Toner said Secretary of State Hillary Clinton had spoken with her Egyptian counterpart.

“We ask Egypt to use its influence in the region to help de-escalate the situation,” he said.