Israel will not stop its military operation in Gaza until “complete quiet” has been achieved, the country’s defence minister has said, as airstrikes and rocket fire continued throughout Wednesday. As the death toll from the most serious conflict between Israel and the Palestinians for nine years mounted, international leaders called for restraint amid fears of a full-scale war. At the same time of the exchange of bombs and rockets between Israel and Gaza, there has been an upsurge in ethnically motivated attacks in mixed neighbourhoods inside Israel by both Jewish and Arab mobs. Joe Biden spoke to the Israeli prime minister Benjamin Netanyahu saying: “My expectation and hope is that this will be closing down sooner than later”, but he added Israel had the right to defend itself against incoming rockets. Russia called for an urgent meeting of the “quartet” of mediating powers: the US, Russia, UN and the EU, a call supported by the UN secretary general, António Guterres. The Israeli military said it had killed four senior Hamas commanders and a dozen more Hamas operatives in a series of strikes. It said it had undertaken a “complex and first-of-its-kind operation” jointly with the Shin Bet security service. The dead included Bassem Issa, the Gaza City Brigade commander, the head of the cyber-command and the head of Hamas’s production network, said a security agency statement. “We eliminated senior Hamas commanders and this is just the beginning,” Netanyahu said. “We will inflict blows on them that they couldn’t even dream of.” The Israeli military would use “increasing force”, he added. Hamas’s armed wing later confirmed the death of a senior commander and a number of fighters. “The Izz ad-Din al-Qassam Brigades take pride in … the martyrdom of the commander Bassem Issa,” a statement said. The killings are likely to harden Hamas’s resolve to continue its rocket assaults on Israel. After the Israeli military operation, Hamas fired 50 rockets towards Ashdod, a city close to the Gaza border. Sirens sounded every few minutes on Wednesday afternoon in towns and communities close to the border. Amid reports that Egyptian mediators were attempting to broker a deal to end the fighting, Benny Gantz, the Israeli defence minister, said: “Israel is not preparing for a ceasefire. There is currently no end date for the operation. Only when we achieve complete quiet can we talk about calm.” He added: “We will not listen to moral preaching against our duty to protect the citizens of Israel.” Jonathan Conricus, a spokesperson for the Israeli army, said he expected the fighting to intensify. Asked about a possible ceasefire, he said: “I don’t think my commanders are aware, or particularly interested.” Israel’s cabinet was due to meet on Wednesday evening to discuss the worsening situation, and an Egyptian delegation was expected to enter Gaza for ceasefire talks. Egypt has been a key player in brokering ceasefires in previous conflicts between Israel and Gaza. Since Monday, the Israeli military has carried out hundreds of airstrikes in Gaza and Palestinian militant groups have fired multiple rocket barrages at Israeli cities. Two high-rise buildings containing flats and offices in Gaza City have been targeted. Gaza’s death toll has risen to 65, including 16 children, according to the health ministry. More than 300 people have been wounded. Six Israeli civilians, including two children – one of them a six-year-old – have been killed by rocket fire and dozens wounded. Towns in Israel with mixed Jewish and Arab populations have also experienced violent clashes. In Bat Yam, a Tel Aviv suburb, a crowd of Jewish ultra-nationalists attacked a car they believe was being driven by an Arab, dragging the driver out of the car and beating him. The victim was hospitalised with serious injuries. In Lod, a town south of Tel Aviv, the mayor warned of “civil war” and called for the Israeli military to restore calm. Police units were redeployed from the West Bank to Lod as people threw rocks and set fire to cars and buildings, including synagogues. In Acre to the north, an Arab mob attacked and critically injured a Jewish man, and attacked the ambulance talking him to hospital. Tor Wennesland, the UN’s Middle East envoy, said leaders on all sides must “take the responsibility of de-escalation”. Before briefing the 15 members of the UN security council on the crisis on Wednesday – its second such meeting in three days – Wennesland warned: “The cost of war in Gaza is devastating and is being paid by ordinary people. Stop the fire immediately. We’re escalating towards a full-scale war.” A White House account of the Wednesday’s phone call between Biden and Netanyahu said that the US president had “conveyed his unwavering support for Israel’s security and for Israel’s legitimate right to defend itself and its people, while protecting civilians.” “He also conveyed the United States’ encouragement of a pathway toward restoring a sustainable calm,” a White House statement said. But the US blocked a unified security council statement on the situation, arguing it would be unhelpful while contacts with leaders in the region were continuing. The secretary of state, Tony Blinken, said that Hady Amr, the deputy assistant secretary of state for Israel and Palestinian affairs, would travel to the region immediately to meet Israeli and Palestinian leaders. The White House said it would nominate a candidate for the empty post of US ambassador to Israel in the next few weeks. In the UK, Boris Johnson urged Israeli and Palestinian leaders to “step back from the brink”. Calling for both sides to show restraint, the prime minister said: “The UK is deeply concerned by the growing violence and civilian casualties and we want to see an urgent de-escalation of tensions.” In parliament, the Foreign Office minister James Cleverly said Israel had an absolute legitimate right of self-defence but its actions must be proportionate, cautious and dedicated to avoiding civilian casualties. Urging an end to the cycle of violence and any kind of provocation, he described Hamas attacks on Israel as “acts of terrorism”, adding “they must permanently end their incitement and rocket fire against Israel”. The UK government was in contact with both Israeli and Palestinian ministers in an attempt to calm the crisis, he said. The Conservative MP Richard Graham said the Israeli military had “effectively attacked the al-Aqsa mosque, the centre of Islamic worship in Jerusalem for hundreds of years”. Although the Hamas attacks were unacceptable, “a major cause of the increased discontent was the number of illegal convictions from East Jerusalem”, he said. While most international leaders called for restraint on both sides, Recep Tayyip Erdoğan, the Turkish president, bucked the trend by demanding in a phone call with the Russian leader, Vladimir Putin, that the international community “give Israel a strong and deterrent lesson” over its conduct toward the Palestinians. In recent weeks, anger has grown over Israel’s half-century occupation, its ever-deepening military grip over Palestinian life and a wave of evictions and demolitions. In Jerusalem, hundreds of Palestinians have been wounded in near-nightly protests that escalated over the weekend and spread to other areas of Israel and the occupied West Bank. Israel and Hamas have fought three wars, which were largely seen as failures for both sides, with Hamas still in power and Israel continuing to maintain a crippling blockade.