At least three Palestinians were killed and many more injured overnight as the Israel-Gaza conflict continues.

Hamas, the Palestinian militant group that governs Gaza, said its leader's home was bombed on Sunday morning in a wave of air strikes on the Gaza Strip.

In response rocket barrages were fired at Tel Aviv as hostilities stretched into a seventh day with no sign of stopping.

As heavy bombardment roared through the night, health officials confirmed at least 148 have been killed in Gaza since the violence began on Monday, including 41 children.

Israel has reported 10 dead, including two children.

Both Israel and Hamas have insisted they would continue their cross-border fire, a day after Israel destroyed a 12-storey building in Gaza City that had housed the U.S. Associated Press and Qatar-based Al Jazeera media operations.

The Israel military said the al-Jala building was a legitimate military target, containing Hamas military offices, and that it had given warnings to civilians to get out of the building before the attack.

A missile falls as smoke rises near a tower housing AP, Al Jazeera offices (C) during Israeli missile strikes in Gaza city, May 15, 2021. REUTERS/Ashraf Abu Amrah NO RESALES. NO ARCHIVES.
Three heavy missiles levelled the 12-storey building in Gaza home to Associated Press

The AP condemned the attack, and asked Israel to put forward evidence. "We have had no indication Hamas was in the building or active in the building," the news organisation said in a statement.

Shadow foreign secretary Lisa Nandy described the attack on the offices The Associated Press, Al-Jazeera and others as "completely unacceptable", adding that "press freedom is a fundamental right".

In what it called a reprisal for Israel's destruction of the al-Jala building, Hamas fired rockets at Tel Aviv and towns in southern Israel early on Sunday.

Envoys from the United States, United Nations and Egypt were working to restore calm but have yet to show any signs of progress. The U.N. Security Council was due to meet later on Sunday to discuss the worst outbreak of Israeli-Palestinian violence in years.

Prime Minister Benjamin Netanyahu said late on Saturday that Israel was "still in the midst of this operation, it is still not over and this operation will continue as long as necessary."

Smoke rises as the building collapses after an Israeli airstrike hits Al-Jalaa tower, which houses apartments and several media outlets, including The Associated Press and Al Jazeera, in Gaza City, 15 May 2021. In response to days of violent confrontations between Israeli security forces and Palestinians in Jerusalem, various Palestinian militants factions in Gaza launched rocket attacks since 10 May that killed at least nine Israelis to date. According to the Palestinian Ministry of Health, at least 139 Palestinians, including 39 children, were killed in the recent retaliatory Israeli airstrikes.
At least 148 have been killed in Gaza since the violence began on Monday, including 41 children

In a burst of air strikes early on Sunday, Israel targeted the home of Yehya Al-Sinwar, who since 2017 has headed the political and military wings of Hamas in Gaza, the group's TV station said.

Hamas began its rocket assault on Monday after weeks of tensions over a court case to evict several Palestinian families in East Jerusalem, and in retaliation Israeli police clashed with Palestinians near the city's Al-Aqsa Mosque, Islam's third holiest site, during the Muslim holy month of Ramadan.

Hamas, Islamic Jihad and other militant groups have fired around 2,300 rockets from Gaza since Monday, the Israeli military said on Saturday. It said about 1,000 were intercepted by missile defences and 380 fell into the Gaza Strip.

Israel has launched more than 1,000 air and artillery strikes into the densely populated coastal strip, saying they were aimed at Hamas and other militant targets.

Earlier this week, the International Criminal Court's chief prosecutor, Fatou Bensouda, told Reuters the court was "monitoring very closely" the latest escalation of hostilities, amid an investigation now under way into alleged war crimes in earlier bouts of the conflict.

A ball of fire erupts from the Jala Tower as it is destroyed in an Israeli airstrike in Gaza city controlled by the Palestinian Hamas movement, on May 15, 2021. - Israeli air strikes pounded the Gaza Strip, killing 10 members of an extended family and demolishing a key media building, while Palestinian militants launched rockets in return amid violence in the West Bank. Israel's air force targeted the 13-floor Jala Tower housing Qatar-based Al-Jazeera television and the Associated Press news agency in the Gaza Strip. (Photo by MAHMUD HAMS / AFP) (Photo by MAHMUD HAMS/AFP via Getty Images)
A ball of fire erupts from the Jala Tower in Gaza
Palestinian protesters hurl stones during clashes with Israeli forces in the Shuafat camp for Palestinian refugees, neighbouring the Israeli settlement of Ramat Shlomo, in Israeli-annexed east Jerusalem on May 14, 2021. - Israel faced a widening conflict, as deadly violence escalated across the West Bank amid a massive aerial bombardment in Gaza and unprecedented unrest among Arabs and Jews inside the country. The West Bank clashes, described as among the most intense since the second intifada that began in 2000, left seven people dead from Israeli fire, the Palestinian health ministry said, as the death toll from strikes in Gaza rose to 122. (Photo by Ahmad GHARABLI / AFP) (Photo by AHMAD GHARABLI/AFP via Getty Images)
Both Israel and Hamas have insisted they will continue their cross-border fire

Netanyahu accused Hamas of "committing a double war crime" by targeting civilians, and using Palestinian civilians as "human shields."

U.N. Secretary-General Antonio Guterres reminded "all sides that any indiscriminate targeting of civilian and media structures violates international law and must be avoided at all costs," U.N. spokesman Stephane Dujarric said in a statement on Saturday.

President Joe Biden's envoy, Hady Amr, arrived in Israel on Friday for talks. Biden spoke with both Netanyahu and Palestinian President Mahmoud Abbas late on Saturday, and updated them on U.S. diplomatic efforts, the White House said.

But any mediation is complicated by the fact that the United States and most western powers do not talk to Hamas. And Abbas, whose power base is in the occupied West Bank, exerts little influence over Hamas in Gaza.

In Israel, the conflict has been accompanied by violence amongst the country's mixed communities of Jews and Arabs, with synagogues attacked and Arab-owned shops vandalised.

There has also been an upsurge in deadly clashes in the occupied West Bank. At least 12 Palestinians have been killed by Israeli troops in the occupied West Bank since Friday, most of them during clashes.