Rishi Sunak has urged MPs not to rush to judgment over the blast at a hospital in Gaza, as he was repeatedly urged by the Labour leader, Keir Starmer, to remind Israel to respect international law. Sunak said British intelligence was working at pace to analyse evidence and “to get to the bottom” of the explosion at al-Ahli Arab hospital that was reported to have killed hundreds of civilians. The prime minister said he would meet some of the families of hostages held by Hamas in Gaza and that the UK was working closely with the government of Qatar, which he said was taking a lead in attempting to secure the release of those held since the attacks on Israel 11 days ago. The Israeli military produced evidence on Wednesday morning that it said showed the blast was the result of a rocket launched by the militant group Islamic Jihad misfiring. The group denied responsibility. The Gaza health ministry, run by Hamas, has blamed an Israeli strike for the blast, which a ministry spokesperson said killed 471 people. Visiting Tel Aviv, the US president, Joe Biden, appeared to side with the Israeli prime minister, Benjamin Netanyahu, by telling him it “appears as though it was done by the other team, not you”. But Sunak told the House of Commons he was unable to reveal the UK verdict on who was behind the strike after holding talks with the national security adviser and the joint intelligence committee. Starmer made an appeal for parliament to “speak with one voice” in condemning terrorism, supporting Israel’s right to self-defence, urging respect for “the dignity of all human life” and maintaining international law. He described the strike on the hospital as “incredibly distressing”, and said the fears of people in Gaza that there was no place of safety were “profound”. He added: “The lights are going out and the innocent civilians of Gaza are terrified that they will die in the darkness, out of sight. International law must always be followed. Hamas are not the Palestinian people and the Palestinian people are not Hamas.” The foreign secretary, James Cleverly, speaking in the Commons, said that – despite the clamour for independent assessors to examine the blast site to determine who was responsible – practically that was “incredibly difficult”. He echoed Sunak in urging people not to rush to judgment, saying this would only fuel instability in the Middle East and risk shattering community cohesion in the UK. Cleverly said the definitive conclusions of the Foreign Office and MI6 would be made public once they were reached. Cleverly said he was returning to the Middle East this week. His first stop is understood to be Egypt on Thursday. Cleverly said recent events had been a “setback” to the UK’s aim of a two-state solution for Israel and Palestine. But he said the government was not “fatalistic” that such an outcome was now impossible. The Scottish National party’s Westminster leader, Stephen Flynn, called for a ceasefire – a position not held by the Conservatives and Labour – and went on to ask if the government was considering setting up a refugee resettlement scheme for Palestinians, similar to schemes set up for Syrians, Afghans and Ukrainians. Sunak replied by saying Israel had a right to defend itself and added that “unlike Hamas”, the Israeli government had made it clear that its forces would operate within accordance of international law. He did not directly answer the question about a resettlement scheme, saying instead that the UK was contributing to UN initiatives to support refugees. Amid tense scenes, those pressing the prime minister included one of his own backbenchers, the former foreign affairs committee chair Crispin Blunt, who referred to reports that Sunak would be travelling to Israel, where he would see “the shock and trauma throughout the Israeli nation, which was also accompanied by rage”. Blunt said that the Israeli reaction – led by a president who he said would be held accountable for an intelligence failure – “is going to amount to, is indeed amounting to” a war crime. Sunak said that, “as a friend”, the UK would always urge Israel to take every step to avoid harming civilians, adding that Hamas was a terrorist organisation that embedded itself within the civilian population. After PMQs, Sunak held meetings with British-Israeli families whose relatives are believed to be among those being held hostage by Hamas. Those in the meetings included Sharone Lifschitz, whose elderly parents are among the missing. At least seven British nationals have been killed, including 13-year-old Yahel Sharabi, with at least another nine missing. Cleverly’s visit to Arab states, starting in Egypt on Thursday, is an attempt to improve relations with leaders angry at the UK’s refusal to back a ceasefire. He was also expected to travel to Qatar, Turkey and possibly Bahrain, UK sources said, emphasising his travel plans were fluid. In Egypt, Cleverly is expected to focus on the opening of the Rafa crossing, including plans for a safe space to be established in southern Gaza to which aid can be sent. The opening of the aid corridor should allow foreign nationals inside Gaza over the border into Egypt.