Egyptian Prime Minister Hisham Qandil crossed into Gaza Friday for a brief visit amid a massive Israeli military campaign against militants in the Hamas-run territory.

Shortly ahead of his arrival at the Rafah crossing, Israel said it would during his visit halt its relentless aerial campaign against the Gaza Strip, which has angered Egypt and sent tensions soaring across a Middle East already shaken by Arab Spring uprisings and a civil war in Syria.

"The Egyptian prime minister has arrived at the Rafah crossing and officials from the Palestinian (Hamas) government are welcoming him on the Palestinian side," a security source said.

Officials in Gaza said Qandil would meet with top members of the ruling Islamist Hamas movement on a brief visit.

Egypt's Islamist President Mohamed Morsi -- who hails from the Muslim Brotherhood movement that gave birth to Hamas -- warned on Thursday that Egypt would not accept Israel's "aggression" in the Gaza Strip.

Israeli warplanes carried out relentless sorties over the Gaza Strip through the night while Palestinian militants fired more rockets into the Jewish state, which on Thursday agreed in principle for the call-up of 30,000 reservists and warned it would expand its operation.

Early on Friday Israel said it had agreed to an Egyptian request to cease fire during Qandil's visit, which an Israeli official said is expected to last around three hours, on condition Gaza militants held their rocket fire.

The escalating conflict, which has so far killed 18 Palestinians and three Israelis, who died in rocket fire, has drawn expressions of deep concern internationally and sparked anger in the Arab and Muslim world.

As dawn broke in the tiny Palestinian enclave, Israeli war planes carried out multiple new air strikes, including several hits on Gaza City as Israel's Operation Pillar of Defence, aimed at stamping out rocket fire, entered its third day.

"There have been 130 strikes overnight until now," Hamas interior ministry spokesman Islam Shahwan said, citing 'tens of strikes' across Gaza on Friday morning.

The bloodshed began on Wednesday afternoon when Israel killed top Hamas military chief Ahmed Jaabari, sparking a massive escalation.

On the ground in Gaza emergency services spokesman Adham Abu Selmiya said the toll now stood at 18 Palestinians, several of them children, with a further 235 people injured in just over 36 hours of Israeli strikes.

The health ministry had earlier said 19, but later revised down its toll. And the Israeli army said it had carried out 466 air strikes since it launched the operation on Wednesday afternoon with the targeted killing of top Hamas military commander Ahmed Jaabari.

The army said 11 Palestinian rockets had been fired at Israel overnight.

A total of 280 rockets have been fired at the Jewish state from Gaza since Wednesday afternoon, killing three Israelis on Thursday and injuring 19. Israel's vaunted Iron Dome anti-missile system intercepted another 131 of those, a spokesperson said.

As Israel's leadership vowed to do whatever necessary to bring quiet to the area, military sources warned that "an excessive amount of weapons storage facilities" had been "deliberately located inside civilian residential buildings."

"In the past 24 hours, Israel has made it clear that it will not tolerate rocket and missile attacks on its civilians," Israeli Prime Minister Benjamin Netanyahu said on Thursday.

Shortly afterwards, a rocket hit the sea just south of Tel Aviv, the farthest distance ever attained by fire from Gaza, in an attack claimed by the armed wing of Islamic Jihad.

Israeli news networks said it was the first time rockets had been fired at Tel Aviv since the 1991 Gulf War, when the city was hit by Iraqi Scud missiles.

The White House said there was "no justification" for rocket attacks on Israel, blaming Hamas for the explosion of violence.