The US and Israel have marked the first “day after Hamas” after Israel revealed it had finally eliminated the mastermind of the October 7 attacks.

Hamas leader Yahya Sinwar was the top target on Israel’s most-wanted list in its year-long war against the terrorist group.

The Israeli government said on Friday (AEDT) it had killed Sinwar during a military operation in the Gaza Strip.

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.

US President Joe Biden said the news was “a good day for Israel, for the United States and for the world.

“I will be speaking soon with Prime Minister Netanyahu and other Israeli leaders to congratulate them, to discuss the pathway for bringing the hostages home to their families, and for ending this war once and for all, which has caused so much devastation to innocent people,” Biden’s written statement said.

“There is now the opportunity for a ‘day after’ in Gaza without Hamas in power, and for a political settlement that provides a better future for Israelis and Palestinians alike.

“Yahya Sinwar was an insurmountable obstacle to achieving all of those goals. That obstacle no longer exists. But much work remains before us,” Biden said.

Netanyahu said: “This is the beginning of the day after Hamas.

“Evil has suffered a heavy blow, but the task before us is not yet complete.”

He said Sinwar’s death was an “important moment in the war”.

“Now it is clear to everyone, in Israel and in the world, why we insisted on not ending the war.”

There has been no official comment from Hamas but sources in the group said the indications were 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,” Foreign Minister Israel Katz confirmed.

“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.”

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.

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.

Israel’s Army Radio previously said the incident occurred during a ground operation in the city of Rafah in the southern Gaza Strip, during which Israeli troops killed three militants and took their bodies.

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.

-with AP and Reuters