An Israel airstrike in Gaza killed at least 18 people, all from the same family, on Saturday, hours after mediators expressed optimism for an imminent cease-fire deal between Israel and Hamas.Officials from the United States, Egypt and Qatar ended two days of cease-fire talks and expressed hope that a deal could be reached in the 10-month-old war. A joint statement said a proposal to bridge gaps between Israel and Hamas was presented and they expect to work out implementation details next week in Cairo.The mediation efforts aim to secure the release of scores of Israeli hostages and stop the fighting that has devastated Gaza, where the death toll has surpassed 40,000 and a possible polio outbreak is feared. Talks are also meant to calm regional tensions that have threatened to explode into a wider war if Iran and Hezbollah militants in Lebanon attack Israel in retaliation for recent killings of militant leaders.Saturday's airstrike hit a house and adjacent warehouse sheltering displaced people at the entrance to the town of Zawaida, according to the Al-Aqsa Martyrs Hospital in Deir al-Balah, where casualties were taken. An Associated Press reporter there counted the dead.Among those killed was Sami Jawad al-Ejlah, a wholesaler who coordinated with the Israeli military to bring meat and fish to Gaza. The dead also included his two wives, 11 of their children ages 2 to 22, the children’s grandmother and three other relatives, according to a list provided by the hospital.“He was a peaceful man,” said Abu Ahmed, a neighbor. More than 40 civilians were sheltering in the house and warehouse at the time, he said.The Israeli military, which rarely comments on individual strikes, said it struck “terrorist infrastructure” in central Gaza where rockets had been fired toward Israel in recent weeks. It said it was continuing attacks on militants in central Gaza.Another mass evacuation is ordered in GazaAnother mass evacuation was ordered for parts of central Gaza. Israeli military spokesperson Avichay Adraee in a post on X said cited Palestinian rocket fire and said Palestinians in areas in and around the urban Maghazi refugee camp should leave.“The suffering began from the day we left our homes," said Ahmad Omrani, one of those affected by the order, as heavily laden vehicles, bikes and donkey carts weaved through the rubble. "We suffer from fear and anxiety, and fear for the children playing in the street. You cannot sleep, sit or eat well.”The vast majority of Gaza’s population has been displaced, often multiple times, and around 84% of the territory has been put under evacuation orders by the Israeli military, according to the United Nations.The war began when Hamas-led militants stormed across the border on Oct. 7, killing about 1,200 people, mostly civilians, and abducting 250 to Gaza. More than 100 were released in a November cease-fire. Around 110 are believed to be in Gaza, though Israeli authorities believe around a third are dead.Israel says it has killed more than 17,000 Hamas militants, without providing evidence.Gaza's Health Ministry said Saturday at least 40,074 Palestinians have been killed in the war. The ministry does not distinguish between fighters and civilians.In the Israeli-occupied West Bank, Israel's military said it struck a “terrorist cell” in Jenin. The health ministry there said two bodies were taken to a government hospital.Cease-fire and implementation plansMediators have spent months pursuing a three-phase plan in which Hamas would release the hostages in exchange for a lasting cease-fire, the withdrawal of Israeli forces from Gaza and the release of Palestinians imprisoned by Israel.Efforts took on new urgency in recent weeks after the killing of a top Hezbollah commander in an Israeli airstrike in Beirut and of Hamas’ top political leader in an explosion in Tehran that was widely blamed on Israel.Israel and Hezbollah have traded fire since the war started. An Israeli strike Saturday killed at least 10 Syrians, including a woman and her two children, Lebanon’s Health Ministry said. Israel said it targeted a Hezbollah weapons depot.In an apparent sign of confidence, mediators were beginning preparations for implementing the cease-fire proposal even before its approval, said an American official, who spoke on condition of anonymity in keeping with rules set by the White House.Israel's negotiating team expressed to Prime Minister Benjamin Netanyahu “cautious optimism for the possibility to move toward a deal,” a statement from his office said Saturday.An Israeli official said a delegation was set to travel to Cairo on Sunday to continue talks. The official spoke on condition of anonymity because they weren’t authorized to discuss the sensitive talks with the media.But Hamas has cast doubt on whether an agreement was near, saying the latest proposal diverged significantly from a previous iteration they had accepted in principle. Hamas has rejected Israel’s demands that include a lasting military presence along the border with Egypt and a line bisecting Gaza where it would search Palestinians returning to their homes to find militants.Israel showed flexibility on retreating from the border corridor, and a meeting between Egyptian and Israeli military officials was scheduled for next week to agree on a withdrawal mechanism, according to two Egyptian officials, who spoke on condition of anonymity because they were not authorized to discuss the private negotiations.___Magdy reported from Cairo. Associated Press writer Tia Goldenberg in Tel Aviv, Israel, contributed.