The Israeli military announced the death of Hamas chief Yahya Sinwar, mastermind of the attack on October 7, 2023, after a group of soldiers killed him in a surprise firefight in southern Gaza's Rafah.

His death is a massive blow to the Palestinian militant movement that has waged a war with Israeli forces in the Gaza Strip for more than a year now.

Here is what we know about the killing of Israel's most wanted man.

How was Sinwar found and killed?

According to the Israeli military, Sinwar met his end at the hands of a routine patrol on Wednesday.

It said a group of soldiers of the 828th Brigade (Bislach) was moving through the city of Rafah when it came across three Palestinian militants.

Israeli media and military officials said there was no prior intelligence pointing to Sinwar's presence in the area.

"Sinwar hid in places that our forces have explored over a long period of time," military spokesman Daniel Hagari said Thursday.

"The forces identified three terrorists who were going from home to home on the run," Hagari said.

As the soldiers chased them, Sinwar split from the other two, the military reported.

The military said a tank later fired at the building where two of the militants hid and at the one where Sinwar took cover, it said.

"Sinwar ran away alone into one of the buildings and our forces scanned the area with a drone," Hagari said.

Footage released by the military showed Sinwar covered in dust sitting in an armchair staring down a drone as the device entered the house devastated by strikes.

The grainy footage showed Sinwar alone with one hand severely injured and his head covered in a traditional scarf, throwing a stick at the approaching drone during his final moments.

"We identified him as a terrorist inside a building and we shot into the building and we entered to scan the area. We found him with a gun and 40,000 shekels ($10,750)," Hagari said.

Forensic lab findings

Unverified images circulating online showed Israeli soldiers circling the mangled corpse of a man resembling Sinwar who appeared to have suffered a severe head wound.

The man was wearing a chunky watch and surrounded by rubble.

The military conducted immediate DNA testing along with dental examinations and other forensic enquiries that helped confirm Sinwar's identity.

Later on Thursday, Sinwar's body was brought to a laboratory in Tel Aviv.

The initial findings described Sinwar's physical condition as "good even though he had spent a long time in tunnels", Kan, an Israeli public broadcaster, reported.

An autopsy found that Sinwar was killed by a gunshot to the head, the doctor who oversaw the procedure told The New York Times on Friday.

Dr Chen Kugel said Sinwar was wounded in the arm by shrapnel, perhaps from a missile or tank shell, before he apparently tied an electric cable around his arm as a makeshift tourniquet. 

That "wasn't strong enough and his forearm was smashed", Kugel said.

He said a gunshot killed Sinwar, though The New York Times noted it was unclear who fired the shot or when, and what weapon was used.

No hostages

Sinwar had not been seen in public since the war erupted with the October 7, 2023 attack on Israel.

The Israeli military and media regularly claimed he was hiding deep in the warren of tunnels under Gaza, while images released by the army earlier this year showed CCTV footage of a man exiting a tunnel it claimed was Sinwar.

There were also reports that Sinwar had surrounded himself with several hostages who were seized by militants during the October 7 onslaught.

But when Sinwar was finally cornered and killed, there were no captives by his side.

"In the building where the terrorists were eliminated, there were no signs of the presence of hostages in the area," a military statement said Thursday.

What happens now?

Israeli Prime Minister Benjamin Netanyahu hailed the killing of Sinwar and said his death could be the "beginning of the end" to the conflict.

Defence Minister Yoav Gallant remained defiant in the wake of the killing, saying Israel would "pursue every terrorist and eliminate them" and bring back the hostages still held in Gaza. 

Families of hostages, however, expressed concern over the fate of their loved ones as they called for a deal to secure their release.

At a Tel Aviv rally just hours after Sinwar's death was announced, Sisil, 60, who gave only her first name, told AFP the killing presented a "once in a lifetime opportunity" for "a hostage deal to end the war".

Hamas later confirmed its leader's death, saying it would take strength from the killing of Sinwar. 

"Yahya Sinwar and all the leaders and symbols of the movement who preceded him on the path of dignity and martyrdom... will only build our movement and resistance in strength," Qatar-based Hamas official Khalil al-Hayya said in a video statement broadcast by Al Jazeera on Friday.

His killing soon after the death of his predecessor, Ismail Haniyeh, in July also begs the question of who might succeed him.