The Israeli military has said that a ceasefire in Gaza would hold after it was seriously tested by an attack that killed two Israeli soldiers and a wave of airstrikes that killed 36 Palestinians.
Aid supplies into the enclave are due to resume on Monday following US pressure, an Israeli security source said, shortly after Israel announced a halt in supplies in response to what it called a "blatant" violation by Hamas of the truce.
A little over a week has passed since the start of the US-proposed ceasefire aimed at ending two years of war.
Israel's military said militants fired at troops in areas of Rafah city that are Israeli-controlled, according to agreed-upon ceasefire lines.
The military said Israel responded with airstrikes and artillery, hitting dozens of Hamas targets. It also said its forces struck "terrorists" approaching troops in Beit Lahiya in the north.
Health officials said at least 36 Palestinians were killed across Gaza, including children.
One airstrike hit a former school sheltering displaced families in the area of Nuseirat, killing four people, according to Al Awda Hospital, which received the casualties.
Another hit a tent in the Muwasi area of Khan Younis in the south, killing at least four people, including a woman and two children, according to Nasser Hospital.
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Israeli Prime Minister Benjamin Netanyahu directed the military to take "strong action" against any ceasefire violations but did not threaten to return to war.
The armed wing of Hamas continued to accuse Israel of multiple ceasefire violations, but said it remained committed to the ceasefire agreement.
It said communication with its remaining units in Rafah had been cut off for months, adding "we are not responsible for any incidents occurring in those areas".
In a statement on social media on Sunday evening, the IDF said it had "begun the renewed enforcement of the ceasefire, in line with the terms of the agreement".
"The IDF will continue to uphold the ceasefire agreement and will respond firmly to any violation of it," it added.
An Israeli source told Sky News: "The bottom line is that we're done responding. We are now back to where we were this morning before their attack."
Fearing the truce may collapse, some Palestinians, many of whom have lacked sufficient food for months, rushed to buy goods from the main market in Nuseirat.
Further south in Khan Younis, other families fled their homes and shelters after airstrikes hit nearby.
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Major hurdles still stand in the way of a long-lasting peace in Gaza. An earlier ceasefire collapsed in March when Israel launched a barrage of airstrikes.
The new ceasefire began on 10 October, but for days the Israeli government and Hamas have been trading accusations of ceasefire violations.
A senior Egyptian official involved in the ceasefire negotiations said "round-the-clock" contacts were under way to de-escalate the situation.
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Israel on Saturday pressed Hamas to returning the remains of all 28 dead hostages as promised under the ceasefire, saying the Rafah border crossing between Gaza and Egypt would stay closed "until further notice".
Hamas says it has no reason to keep the bodies of the remaining hostages, but that it needs special equipment
recover corpses buried under rubble.
A Hamas delegation led by chief negotiator Khalil al Hayya has arrived in Cairo to follow up the implementation of the ceasefire deal with mediators and other Palestinian groups.
The next stages are expected to focus on disarming Hamas, Israeli withdrawal from additional areas it controls in Gaza, and future governance of the devastated territory.
The US plan proposes the establishment of an internationally-backed authority.