Israeli planes renewed air strikes in Gaza early on Saturday and Hamas fighters responded by firing rockets into Israel as the fighting entered a fifth night and US and Arab diplomats sought an end to the violence.

Palestinian medics said at least 12 people were killed overnight in air strikes throughout Gaza. Health officials said a woman and her three children were among the dead after their house was hit in a refugee camp.

The Israeli military said it carried out strikes on a Hamas military intelligence facility and a number of rocket launching sites in northern Gaza.

The Palestinian religious affairs ministry said Israeli planes destroyed a mosque. A military spokesman said the army was checking the report.

Across the border, sirens sounded throughout much of southern Israel, sending residents running for shelter. In the cities of Beersheba and Ashdod, buildings were struck by rockets. There were no immediate reports of injuries.

With no sign of an end to the violence, casualties spread further afield, with Palestinians reporting on Friday 11 killed in the occupied West Bank due to attacks by Israeli security forces.

At least 132 people have been killed in Gaza since Monday, including 32 children and 21 women, and 950 others wounded, Palestinian medical officials said.

Among the eight dead in Israel were a soldier patrolling the Gaza border and six civilians, including two children, Israeli authorities said.

Ahead of a session of the UN Security Council on Sunday to discuss the situation, Biden administration envoy Hady Amr, Deputy Assistant Secretary for Israel and Palestinian Affairs, flew in on Friday.

The US Embassy in Israel said the aim was “to reinforce the need to work toward a sustainable calm”.

Israel launched day-long attacks on Friday to destroy what it claimed were several kilometres of tunnels, launch sites and weapons manufacturing warehouses used by Hamas' fighters in an effort to halt the rocket attacks.

Across central and southern Israel, from small towns bordering Gaza to metropolitan Tel Aviv and southern Beersheba, people have adjusted to sirens wailing, radio and TV broadcast interruptions and the beeps of cellphones bearing red alerts that send them rushing for cover.

Cross-border hostilities between Israel and Palestinian militants in Gaza have been accompanied by violence in mixed communities of Jews and Arabs in Israel. Synagogues have been attacked and street fights have broken out, prompting Israel's president to warn of civil war.

Diplomatic flurry

Egypt was leading regional efforts to secure a ceasefire. Cairo was pushing for both sides to cease fire from midnight on Friday pending further negotiations, two Egyptian security sources said, with Egypt leaning on Hamas and others, including the United States, trying to reach an agreement with Israel.

The foreign ministers of Egypt and Jordan discussed efforts to end the Gaza confrontation and to prevent “provocations” in Jerusalem, Egypt's foreign ministry said.

“The talks have taken a real and serious path on Friday,” a Palestinian official said. “The mediators from Egypt, Qatar and the United Nations are stepping up their contacts with all sides in a bid to restore calm, but a deal hasn't yet been reached.”

The United Arab Emirates on Friday called for a ceasefire and negotiations while offering condolences to all victims of the fighting, citing the promise of September accords that made the UAE and Bahrain the first Arab states in a quarter century to establish formal ties with Israel.

Hamas, the group that rules Gaza, launched rocket attacks on Monday, in retaliation for Israeli police attacking Palestinians near Al Aqsa Mosque, Islam's third holiest site, in East Jerusalem.

The Israeli military said more than 2,000 rockets had been fired from Gaza into Israel since the start of the conflict, around half of them intercepted by missile defence systems and 350 fell into the Gaza Strip.

Civil unrest between Jews and Arabs in Israel itself dealt a strong blow to efforts by Prime Minister Benjamin Netanyahu's opponents to unseat the Israeli leader after a series of inconclusive elections, giving rise to expectations Israelis will go to the polls for an unprecedented fifth time in just over two years.