Hamas's Gaza leader Khalil Al Hayya confirmed on Sunday the killing of the group's senior commander Raed Saad in an Israeli strike a day earlier.
It was the highest-profile assassination of a senior Hamas figure since a Gaza ceasefire deal between Hamas and Israel came into effect in October.
"The Palestinian people are currently going through difficult times and suffering greatly ... with the martyrdom of more than 70,000 people, the latest of whom was the mujahid commander Raed Saad and his companions," Mr Al Hayya said in a televised speech.
Hamas on Sunday mourned the slain commander and said its armed wing, the Al Qassam Brigades, has appointed a new commander to succeed him.
"We affirm that our fighting will not stop and that the assassination of leaders will not weaken us, but will increase our strength, resilience and determination to continue the path they paved with their blood," the group said in a statement.
The Israeli army said it killed the commander in Gaza city on Saturday, in an escalatory move that could further endanger a fragile ceasefire. The attack also killed five people and wounded 25, according to the enclave's health authorities.
The army described him as “one of the architects” of the October 7, 2023, attack carried out by Hamas on southern Israel that caused the devastating war on Gaza.
It also said he was the head of the weapons production headquarters of Hamas's military wing, who was leading the force's “build-up”.
The Israeli army on Saturday said two reserve soldiers were lightly injured “as a result of an explosive device that detonated during an operation to clear the area of terrorist infrastructure in southern Gaza”.
Israeli Prime Minister Benjamin Netanyahu and Defence Minister Israel Katz said in a joint statement that “in response to the detonation of a Hamas explosive device that wounded our forces today in the Yellow Area of the Gaza Strip … [they] instructed the elimination of the terrorist Raed Saad”.
In a speech on Sunday, Mr Al Hayya reaffirmed his group's rejection of all forms of "guardianship and mandate over our people" in Gaza.
He said that the role of a proposed US-led “board of peace" is to oversee the implementation of the ceasefire agreement and to fund and supervise the reconstruction of the Gaza Strip.
"We also call for the immediate formation of a technocratic committee of independent Palestinians to administer the Gaza Strip, and we affirm our readiness to fully hand over all responsibilities in all areas and facilitate its work," he added.
Mr Al Hayya also said Hamas's weapons, and what it calls its resistance campaign, were a "legitimate right guaranteed by international laws for all peoples under occupation and are linked to the establishment of the Palestinian state".
"We are open to studying any proposals that preserve this right while guaranteeing the establishment of an independent Palestinian state and self-determination for our Palestinian people," he said.
Under the US-brokered ceasefire between Israel and Hamas in Gaza, Israeli troops have withdrawn to positions behind the so-called Yellow Line, although they are still in control of more than half the territory.
Mahmoud Bassal, Gaza's civil defence spokesman, said five people were killed after “a civilian jeep-type vehicle” was struck near the Nabulsi roundabout in Tel Al Hawa.
Mr Bassal said the “charred” bodies were taken to Al Shifa Hospital after “Israeli warplanes targeted the civilian vehicle with three missiles, causing it to burn and its destruction”.
He also said two boys aged 17 and 18 were killed by Israeli fire in two separate incidents in Gaza.
