The dozens of strikes Israel carried out on Hamas positions in southern Gaza Sunday came after it accused the militant group of targeting its troops in "a blatant violation" of the nine-day-old truce.

Asked by reporters whether the truce was still in effect, Trump said: "Yeah, it is". The US president, who helped broker the deal, also suggested that Hamas leadership was not involved in any alleged breaches, instead blaming "some rebels within".

"We want to make sure that it's going to be very peaceful with Hamas," Trump said. "It's going to be handled toughly, but properly."

Gaza's civil defense agency, which operates under Hamas authority, said the strikes killed at least 45 people across the territory.

Four hospitals in Gaza confirmed the death toll of 45 to AFP, saying they had received the dead and wounded.

Israel's military said it was looking into the reports of casualties.

Media restrictions in Gaza and difficulties in accessing many areas mean AFP is unable to independently verify the tolls and details provided by the civil defense agency or the Israeli military.

The army said it had "renewed enforcement of the ceasefire" on Sunday but vowed to "respond firmly to any violation of it".

Hamas denied the accusations, one official accusing Israel of fabricating "pretexts" to resume the war.

A security official also told AFP that Israel was suspending the entry of aid into Gaza due to ceasefire violations.

Israel repeatedly cut off aid to Gaza during the war, exacerbating dire humanitarian conditions, with the United Nations saying it caused a famine there.

The ceasefire, which began on October 10, halted more than two years of devastating war between Israel and Hamas.

The deal established the outline for hostage and prisoner exchanges, and proposed an ambitious roadmap for Gaza's future. But it has quickly faced challenges to its implementation. 

Israel said on Sunday that two of its soldiers died in clashes in the city of Rafah. 

"Earlier today, terrorists fired anti-tank missiles and opened fire on IDF (Israeli army) forces," in Rafah, the military said in a statement. "The IDF responded with air strikes by fighter jets and artillery fire, targeting the Rafah area." 

Palestinian witnesses told AFP clashes erupted in the southern city in an area still held by Israel.

One witness, a 38-year-old man who asked not to be named, said that Hamas had been fighting a local Palestinian gang known as Abu Shabab but the militants were "surprised by the presence of army tanks".

"The air force conducted two strikes from the air," he added.

Abdullah Abu Hasanin, 29, from Al‑Bureij camp in central Gaza where Israel launched strikes, said: "The situation is as if the war has returned anew.

"We had hoped the agreement would hold, but the occupation respects nothing -- not an agreement, not anything."

He said he had rushed to the site of the bombing to help, adding: "The scene is indescribable. Blood has returned again."

AFP images from Bureij showed Palestinians running for cover from the strikes, as well as the dead and wounded arriving at Deir al-Balah hospital, accompanied by grieving relatives.

Defense Minister Israel Katz warned Hamas would "pay a heavy price for every shot and every breach of the ceasefire", adding Israel's response would "become increasingly severe".

A statement from Izzat Al-Rishq, a member of Hamas's political bureau, reaffirmed the group's commitment to the ceasefire.

Israel, it said, "continues to breach the agreement and fabricate flimsy pretexts to justify its crimes".

Hamas's armed wing insisted on Sunday that it had "no knowledge" of any clashes in Rafah.

On Sunday, US Vice President JD Vance called on Gulf Arab countries to establish a "security infrastructure" to ensure that Hamas disarmed -- a key part of the peace deal.

Under Trump's 20-point plan, Israeli forces have withdrawn beyond the so-called Yellow Line. That leaves them in control of around half of Gaza, including the territory's borders but not its main cities.

Hamas in turn has released 20 surviving hostages and is in the process of returning the remaining bodies of those who have died.

Israel returned the bodies of 15 Palestinians to Gaza on Sunday, bringing the total number handed over to 150, the health ministry in the Hamas-run territory said.

Israel has linked the reopening of the Rafah crossing -- the main gateway into Gaza -- to the recovery of all of the deceased.

Hamas has said it needs time and technical assistance to recover the remaining bodies from under Gaza's rubble.

The war, triggered by Hamas's October 7, 2023 attack on Israel, has killed at least 68,159 people in Gaza, according to the health ministry in the Hamas-run territory, figures the United Nations considers credible.

The data does not distinguish between civilians and combatants but indicates that more than half of the dead are women and children.

Hamas's 2023 attack on Israel resulted in the deaths of 1,221 people, mostly civilians, according to an AFP tally based on official Israeli figures.