Israeli troops massed at Gaza's border on Thursday as air strikes in Gaza continue after tensions soared when Israeli forces attacked worshippers at Jerusalem’s Al Aqsa mosque in the last week of Ramazan.

Meanwhile, Palestinian militants also pounded Israel with rockets, most of which have caused little damage in comparison to the death and destruction in Gaza due to Israel’s high-tech air defence capabilities.

At least 83 people, including 17 children, have been killed in Gaza since Monday from air strikes by Israeli forces while hundreds have been injured, medics said, further straining hospitals already under heavy pressure during the Covid-19 pandemic.

Violence erupted on Monday after Israeli police fired more than a dozen tear gas canisters and stun grenades inside Al Aqsa, Islam's third holiest site, after tensions arose over forced evictions of Palestinians from the Sheikh Jarrah neighbourhood in East Jerusalem.

In renewed air strikes on Gaza, Israel struck a six-storey residential building in Gaza City that it said belonged to Hamas, the Islamist group that controls the Palestinian enclave.

“We are facing Israel and Covid-19. We are in between two enemies,” said Asad Karam, 20, a construction worker, standing beside a road damaged during the air strikes. An electricity pole had collapsed by the road, its wires severed.

Health authorities in Gaza said they were investigating the deaths of several people overnight who they said may have inhaled poisonous gas. Samples were being examined and they had yet to draw any final conclusions, they said.

In retaliatory attacks to the Al-Aqsa raids and Gaza air strikes, one rocket by Palestinian militants crashed into a building near Israel's commercial capital of Tel Aviv, injuring five Israelis, police said. Sirens blared in cities across southern Israel, sending thousands running for shelters.

Seven people have been killed in Israel, its military said.

“All of Israel is under attack. It's a very scary situation to be in,” said Margo Aronovic, a 26-year-old student, in Tel Aviv.

Israel has prepared combat troops along the Gaza border and was in “various stages of preparing ground operations”, a military spokesman said, a move that would recall similar incursions during Israel-Gaza wars in 2014 and 2008-2009.

Read: Israeli attacks on Gaza, militant rocket fire fuel fears of full-scale war

With concern growing that the violence that flared on Monday could spiral out of control, the United States is sending an envoy, Hady Amr, to the region. But efforts to end the worst attacks by Israel in years appear so far to have made no progress.

US President Joe Biden said he hoped fighting “will be closing down sooner than later”. A British minister urged Israel and Hamas to “take a step back” from the escalation.

'Open-ended' confrontation

Israeli Prime Minister Benjamin Netanyahu has vowed to “continue acting to strike at the military capabilities of Hamas” and other Gaza groups.

On Wednesday, Israeli forces killed a senior Hamas commander and bombed several buildings, including high-rises and a bank, which Israel said was linked to the faction's activities.

Hamas signalled defiance, with its leader, Ismail Haniyeh, saying: “The confrontation with the enemy is open-ended.”

In pictures: Hundreds wounded as Israeli forces target Palestinians in weekend of violence

Turkey, whose hosting of Hamas leaders in Istanbul in recent years has contributed to a falling out with Israel, called on Muslim countries to show a united and clear stance over the Israel-Gaza violence.

In the fighting inside Israel, where some in the 21 per cent Arab minority have mounted pro-Palestinian protests, attacks by Jews on Arabs passing by in ethnically mixed areas have worsened.

Over 150 arrests were made overnight in Lod and Arab towns in northern Israel, police said.

Israeli President Reuven Rivlin called for an end to “this madness”.

“We are endangered by rockets that are being launched at our citizens and streets, and we are busying ourselves with a senseless civil war among ourselves,” said the president, whose role is largely ceremonial.

Flights cancelled

A number of foreign carriers have cancelled flights to Israel because of the unrest.

The fatalities in Israel include a soldier killed while patrolling the Gaza border and six civilians, including two children and an Indian worker, medical authorities said.

Meanwhile, Gaza's health ministry said 17 of the people killed in the enclave were children and seven were women.

The Israeli military claimed some 400 of 1,600 rockets fired by Gaza factions had fallen short, potentially causing some Palestinian civilian casualties.

The conflict has led to the freezing of talks by Netanyahu's opponents on forming a governing coalition to unseat him after Israel's inconclusive March 23 election.

Although the forced evictions of Palestinians in Jerusalem were the immediate trigger for hostilities, Palestinians are frustrated by setbacks to their aspirations for an independent state in recent years as Israel expands its illegal occupation of their territories.

These setbacks include Washington's recognition of disputed Jerusalem as Israel's capital, a US plan to end the conflict that they saw as favourable to Israel and settlement building.