Shifa Hospital reported the deaths on Monday amid the months-old ceasefire that has seen continued fighting.
The Israeli army said it was striking targets in response to Israeli troops coming under fire in the southern city of Rafah, which it says was a violation of the ceasefire.
The army said it is striking targets "in a precise manner".
The four-month-old US-backed ceasefire followed stalled negotiations and included Israel and Hamas accepting a 20-point plan proposed by US President Donald Trump aimed at ending the war unleashed by Hamas' October 7, 2023, attack into Israel.
At the time, Trump said it would lead to a "Strong, Durable, and Everlasting Peace".
Hamas freed all the living hostages it still held at the outset of the deal in exchange for thousands of Palestinian prisoners held by Israel and the remains of others.
But the larger issues the agreement sought to address, including the future governance of the strip, were met with reservations, and the US offered no firm timeline.
The United Nations top official on Monday expressed concern about the Israeli security cabinet's decision to deepen the country's control over the occupied West Bank.
Secretary-General Antonio Guterres is "gravely concerned" and warned that the Israeli decision could erode the prospect of a two-state solution, spokesperson Stéphane Dujarric said in a statement.
"Such actions, including Israel's continued presence in the Occupied Palestinian Territory are not only destabilizing but – as recalled by the International Court of Justice – unlawful," he said.
Israel 's security cabinet on Sunday approved measures that aim to deepen Israeli control over the occupied West Bank and weaken the already limited powers of the Palestinian Authority.
Israel's far-right Finance Minister Bezalel Smotrich said the measures would make it easier for Jewish settlers to force Palestinians to give up land, adding that "we will continue to bury the idea of a Palestinian state".
Israel captured the West Bank, as well as Gaza and east Jerusalem, in the 1967 Mideast war. The Palestinians want all three territories for a future state.
The Palestinian official set to oversee day-to-day affairs in Gaza said on Monday that passage through the Rafah crossing with Egypt was starting to improve after a chaotic first week of reopening marked by confusion, delays and a limited number of crossings.
Ali Shaath, head of the National Committee for the Administration of Gaza, told Egypt's Al-Qahera News that operations at the crossing were improving on Sunday.
He said 88 Palestinians were scheduled to travel through Rafah on Monday, more than have crossed in the initial days since reopening.
The European Union border mission at the crossing said in a statement on Sunday that 284 Palestinians had crossed since reopening.
Travellers included people returning after having fled the war and medical evacuees and their escorts. In total, 53 medical evacuees departed during the first five days of operations.
That remains well below the agreed target of 50 medical evacuees exiting and 50 returnees entering daily, negotiated by Israeli, Egyptian, Palestinian and international officials.
The Rafah crossing opened last week for the first time since mid-2024, one of the main requirements for the ceasefire between Israel and Hamas.