Israeli forces and Hamas fighters largely held their fire on Tuesday following the extension of a four-day ceasefire in Gaza by at least two extra days to allow for the release of more hostages. With both sides expressing hope of further extensions, mediator Qatar hosted the spy chiefs from Israel’s Mossad and the United States’ CIA at a meeting to “build on progress”, a source briefed on the visits told a British wire service. A US official confirmed that CIA Director William Burns was in Doha “for meetings on the Israel-Hamas conflict including discussions on hostages”, without elaborating. The truce, which began on Friday, has brought the first respite to the Hamas-ruled Gaza Strip in seven weeks, during which Israel had bombed swathes of the territory into a desolate moonscape. Although conditions on the ground in Gaza remained largely peaceful on Tuesday, Israel’s military said three explosive devices had been detonated near its troops in two different locations in the northern Gaza Strip, “violating the framework of the operational pause”. In one of the locations, gunmen opened fire on the soldiers who returned fire and that “a number of soldiers were lightly injured”. No further details were immediately available. Earlier, a single column of black smoke could be seen rising above the obliterated wasteland of the northern Gaza war zone from across the fence in Israel, but for a fifth day there was no sign of jets in the sky or rumble of explosions. Both sides also reported some Israeli tank fire in the Sheikh Radwan district of Gaza City in the morning, but there were no reports of casualties. Israel said its troops had been approached and fired a warning shot. Lieutenant-General Herzi Halevi, chief of Israel’s armed forces, told a press briefing that the military remained on alert in Gaza and was prepared to continue fighting. “We are using the days of pause within the framework to learn, to bolster our readiness and to approve future operational plans,” he said. Since the truce started on Friday, Hamas has released 69 hostages – 50 Israeli women and children, including some toddlers, as well as 19 foreigners, mainly Thai farmworkers. In return, Israel has released 150 security detainees from its jails, all women and teenagers. Israel has said the truce could be prolonged as long as Hamas continues to release at least 10 Israeli hostages per day. But with fewer women and children left in captivity, keeping the guns quiet beyond Wednesday could require negotiating to free at least some Israeli men for the first time. “We hope the occupation (Israel) abides (by the agreement) in the next two days because we are seeking a new agreement, besides women and children, whereby other categories that we have that we can swap,” Hamas official Khalil Al-Hayya told Al Jazeera late on Monday. Qatar’s foreign ministry said it was now trying to secure a further extension based on Hamas releasing more hostages. Israel has vowed to annihilate Hamas after its gunmen burst across the border fence and went on a rampage, killing around 1,200 people and seizing 240 captives. Since then, Gaza health authorities deemed reliable by the United Nations say more than 15,000 people have been confirmed killed in Israel’s bombardment, around 40% of them children, with many more dead feared to be lost under rubble. More than two-thirds of Gaza’s 2.3 million people have lost their homes, with thousands of families sleeping rough in makeshift shelters with only the belongings they could carry. Drone footage on Tuesday showed hundreds of Gaza residents queuing for water, petrol and natural gas. Many are using the truce to return to abandoned or destroyed homes, like Abu Shamaleh, who was picking through the rubble of his flattened home in Khan Younis, looking for anything recoverable in the masonry. He said 37 family members had been killed and that there was no machinery to excavate the body of a cousin still buried in the ruins. “The truce is the time to lift the rubble and search for all the missing people and bury them. We honour the dead by burying them. What use is the truce if the bodies remain under the rubble?” he said. Among Israeli hostages yet to be freed was 10-month-old baby Kfir Bibas, along with his brother Ariel, 4, and their parents Yarden and Shiri, bundled from a kibbutz by gunmen on Oct 7. Yarden’s sister told reporters relatives had learned the family would not be in the group to go free on Tuesday. Israeli officials said they believed the family was being held by a group other than Hamas. “Kfir… is a child who still doesn’t even know how to say ‘Mommy’,” Jimmy Miller, a cousin, told Channel 12 TV. “We in the family are not managing to function… The family hasn’t slept for a long, long time already – 51 days.” When the war resumes, Israel has made clear it intends to press on with its assault from the northern half of Gaza into the south. US. officials said they have told their ally to be more careful protecting civilians as its forces press on. Israel’s siege has led to the collapse of Gaza’s health care system, especially in the north where no hospitals remain functioning. The World Health Organization said more Gazans could soon be dying of disease than from bombing. There were already a very high number of cases of infants suffering from diarrhoea, said WHO spokesperson Margaret Harris: “No medicines, no vaccination activities, no access to safe water and hygiene and no food.”