Israel expanded evacuation orders in Khan Younis in the southern Gaza Strip overnight, forcing tens of thousands of Palestinian residents and displaced families to leave in the dark as explosions from tank shelling reverberated around them.

The Israeli military said it was attacking militants from the Hamas group – which administered Gaza before the war – who were using those areas to stage attacks and fire rockets. On Saturday, an Israeli airstrike on a school where displaced Palestinians were sheltering in Gaza City killed at least 90 people, according to the civil defence service, prompting an international outcry.

The Israeli military said it had struck a Hamas and Islamic Jihad militant command post, an allegation the two groups rejected as a pretext, and killed 19 militants, Reuters reported.

In Khan Younis in the south of the Gaza Strip, the evacuation instruction covered districts in the centre, east and west, making it one of the largest such orders in the 10-month-old conflict, two days after tanks returned to the east of the city.

The announcement was posted on X and in text and audio messages to residents’ phones: “For your own safety, you must evacuate immediately to the newly created humanitarian zone. The area you are in is considered a dangerous combat zone.”

Hello. We are restarting our live coverage of the Israel-Gaza war and wider Middle East crisis. Here’s a snapshot of the latest.

The West Bank-based Palestinian Authority has made a rare statement after at least 80 people were killed in Israeli missile strikes on a school compound in Gaza City.

A spokesperson for the Palestinian Authority president, Mahmoud Abbas, urged the US – Israel’s most important diplomatic ally and weapons supplier – to “put an end to the blind support that leads to the killing of thousands of innocent civilians, including children, women, and the elderly”.

Hamas denounced it as a “dangerous escalation”, while the Palestinian group’s Lebanese ally Hezbollah called it a “horrific massacre”. Egypt, Qatar and Saudi Arabia have also condemned the strike, which came as mediators were pushing to resume ceasefire talks. Reuters reports that senior Hamas official Sami Abu Zuhri said the strike should serve as a turning point in their efforts.

A separate strike on Saturday killed three Palestinians in Al-Nuseirat in central Gaza and another killed one person in nearby Deir Al-Balah, medics said.

Later in the day an Israeli strike killed three Palestinians in Rafah, near the border with Egypt, medics said.

The Israeli military said the head of general security in Hamas’ military wing, Walid Alsousi, had been killed in southern Gaza. There was no immediate Hamas comment.

In other news:

• The death toll from the Israeli air strike on the Gaza City school has risen to 80, Palestinian health authorities said. The Israeli military acknowledged the strike on the Tabeen school on Saturday morning, claiming it hit a Hamas command centre within the school. Hamas denied having a base at the school. Fadel Naeem, director of the al-Ahli hospital in Gaza City, said the facility received the bodies of 80 people killed in the strike.

• Around 20 Hamas and Islamic Jihad militants were operating from the Gaza City school that was struck by the Israeli air force on Saturday, an Israeli military spokesperson said. “The compound, and the mosque that was struck within it, served as an active Hamas and Islamic Jihad military facility,” lieutenant colonel Nadav Shoshani said on X.

• The presumptive Democratic nominee for the US presidential election addressed Gaza protesters after they interrupted her campaign speech in Glendale, Arizona. Harris stopped her speech looking to the area in the audience where the protesters were chanting from and told them she “respected” their voices. “Let me just speak to that for a moment, and then I’m going to get back to the business at hand,” she said, adding that she believed “now is the time” to agree to a ceasefire and secure the release of hostages held in Gaza.

• The EU’s chief diplomat Josep Borrell has said there is “no justification” for the attack on the school in Gaza. He posted on X: “Horrified by images from a sheltering school in Gaza hit by an Israeli strike, w/ reportedly dozens of Palestinian victims. At least 10 schools were targeted in the last weeks. There’s no justification for these massacres We are dismayed by the terrible overall death toll.” The White House said it was “deeply concerned” about the Gaza school compound strike and asked Israeli officials for further details.

• The Israeli military said in a statement that its air force targeted a command and control centre where Hamas fighters were hiding. The military said it had taken steps to reduce the risk of harming civilians, “including the use of precise munitions, aerial surveillance, and intelligence information”. It did not immediately comment on the casualty reports from Gaza, Reuters reported.

• At least 39,790 Palestinians have been killed and 91,702 have been injured in Israel’s military offensive in Gaza since 7 October, the Gaza health ministry has said in a statement.

• According to the United Nations, 477 out of 564 schools in Gaza have been directly hit or damaged in the war as of July 6. In June, an Israeli strike on a school sheltering displaced Palestinians in central Gaza killed at least 33 people, including 12 women and children, according to local health officials. Israel has blamed the civilian deaths in Gaza on Hamas, saying the group endangers noncombatants by using schools and residential neighborhoods as bases for operations and attacks.

• Iran is set to carry out an order by supreme leader Ayatollah Ali Khamenei to “harshly punish” Israel over the assassination of Hamas leader Ismail Haniyeh in Tehran, a Revolutionary Guards deputy commander was quoted as saying on Friday by local news agencies. Ali Fadavi said Khamenei’s orders were “clear and explicit” and “will be implemented in the best possible way”. White House national security spokesperson John Kirby, asked about Fadavi’s remarks, said the US was ready to defend Israel with plenty of resources in the region, adding: “When we hear rhetoric like that we’ve got to take it seriously, and we do.” When a reporter asked US president Joe Biden on Saturday for his message to Iran, Biden mouthed the word “don’t”.