There has been no official comment from Hamas but sources in the group said the indications suggested that Sinwar had been killed during an Israeli operation in the area of Tal El Sultan, in the Gaza Strip's south.
The Israeli military said in a post on X that Sinwar was dead.
"Mass murderer Yahya Sinwar, who was responsible for the massacre and atrocities of October 7, was killed today by IDF soldiers," Katz said in a written statement from his office.
"This is a great military and moral achievement for Israel and a victory for the entire free world against the axis of evil of radical Islam led by Iran."
Eliminated: Yahya Sinwar.— Israel Defense Forces (@IDF) October 17, 2024
His death represents a major boost to the Israeli military and Prime Minister Benjamin Netanyahu after a string of high-profile assassinations of prominent leaders of its enemies in recent months.
Earlier Israeli police examined dental and DNA evidence to determine if Sinwar, Israel's top target, had been killed.
The military said earlier it was checking the possibility that Sinwar was among three militants killed during an operation in the Gaza Strip.
Al-Majd, a Hamas-linked website that usually publishes about security issues, urged Palestinians to wait for information about Sinwar from the group itself and not Israeli media outlets, which it said aimed to break their spirit.
"Today evil has been dealt a blow," Israeli Prime Minister Benjamin Netanyahu says. (AP PHOTO)
Israeli media reported that the operation was a routine raid that caught Sinwar by chance.
The military said there were no signs that Israeli hostages had been present in the building.
An Israeli security official earlier said it appeared that the man was killed in a battle, not in a planned targeted air strike.
There are a number of possible scenarios for what happens next but Netanyahu said the war would go on.
The Israeli military said it had killed Sinwar in an operation in the southern Gaza Strip on Wednesday.
"After completing the process of identifying the body, it can be confirmed that Yahya Sinwar was eliminated," it said.
In Israel, families of hostages held by Hamas in Gaza said they hoped that a ceasefire could now be reached that would bring home the captives.
In Gaza, pounded relentlessly by Israeli forces for a year, residents said they believed the war would continue but they still clung to their hope of self-determination.
Netanyahu, speaking in Jerusalem just after the death was announced, said Sinwar's death offered the chance of peace in the Middle East but warned that the war in the Gaza Strip was not over and Israel would continue until its hostages were returned.
"Today we have settled the score. Today evil has been dealt a blow but our task has still not been completed," Netanyahu said in a recorded video statement.
"To the dear hostage families, I say: this is an important moment in the war. We will continue full force until all your loved ones, our loved ones, are home."
Another mission accomplished. ✅ — יואב גלנט - Yoav Gallant (@yoavgallant) pic.twitter.com/4QxO52fiABOctober 17, 2024
Israel has samples of Sinwar's DNA from his period in an Israeli jail.
Sinwar has been at the top of Israel's wanted list since the Hamas attack on October 7 last year.
But he had eluded detection, possibly hiding in the warren of tunnels Hamas has built under the Gaza Strip over the past two decades.
Israeli Defence Minister Yoav Gallant posted a message on social media platform X with a biblical quotation.
"'You will pursue your enemies and they will fall before you by the sword.' - Leviticus 26 Our enemies cannot hide. We will pursue and eliminate them."
Previously leader of Hamas in the Gaza Strip, Sinwar was named as its overall leader following the assassination of former political chief Ismail Haniyeh in Tehran in July.
Hamas-led gunmen attacked Israel on October 7, 2023 killing about 1200 people and taking more than 250 hostages into the Gaza Strip.
Israel's campaign in response has killed more than 42,000 people, turned much of Gaza into rubble and displaced most of its population.
AP and Reuters
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