Israel shows video of Hamas chief Sinwar in Gaza tunnel on eve of Oct 7 attack

The Israeli army on Saturday released footage it said showed Hamas leader Yahya Sinwar preparing for a prolonged stay underground in Gaza hours before the Palestinian group launched its October 7 attack.

Sinwar, then Hamas's top figure in the Gaza Strip, is accused of masterminding the unprecedented attack last year that triggered the ongoing war. He was killed by Israeli forces earlier this week.

The footage released by the Israeli military showed Sinwar with his wife and children in a tunnel that army spokesman Rear Admiral Daniel Hagari said was under the family home in Khan Yunis.

"You can see how Sinwar and his family members escape to an underground compound under their house on the night of October 6, just hours before the brutal massacre," Hagari told a televised briefing while showing the grainy footage.

Sinwar, wearing a plain t-shirt, is seen walking through the tunnel with his two children and wife.

"They are alone for hours. Sinwar and his son go up and down, equipping themselves with plates of food, water, pillows, a plasma screen, mattresses and other products for a long stay," said Hagari.

The spokesman showed images of the underground compound which had toilets, showers and a kitchen. He said food, cash and some documents were also found there.

The release of the video comes days after Sinwar was killed by troops in the southern Gaza city of Rafah, in a firefight that ended with the Hamas leader cornered and alone in a destroyed building.

Drone footage, also released by the Israeli military after his death, showed an apparently injured Sinwar throwing an object at the drone in his final moments.

The military has also shared footage showing an Israeli tank firing on the building Sinwar was said to be in.

The New York Times reported that an Israeli autopsy found that Sinwar was killed by a gunshot to the head.

"Sinwar built an underground fortress in his hometown of Khan Yunis. There he hid and continued to launch the attack," Hagari said in his Saturday briefing.

Israeli forces had almost closed on him several times during the war, but he managed to escape, Hagari said.

"For the vast majority of time Sinwar hid underground between Khan Yunis and Rafah," he said of southern Gaza's two main cities.

Israel had identified Sinwar's final hiding after the military found "his DNA sample on a tissue with which he blew his nose," said Hagari.

Hamas dismissed as "blatant lies" Hagari's remarks suggesting that Sinwar had gone into hiding and prioritised his family's well-being over that of other Gazans.

"Commander Yahya Sinwar was martyred after heroically engaging in battle, having led the greatest battle in the history of our Palestinian people," a Hamas statement said.

According to the military, an Israeli patrol encountered Sinwar and two other militants by chance on Wednesday, and as they were chased by soldiers, Sinwar split from the other two.

The military said a tank later fired at the building where Sinwar took cover.

Footage released by the military shortly after Sinwar's death was announced on Thursday showed him covered in dust, sitting in an armchair and staring down a drone as it entered the building, much of it in ruins.

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

"This is actually the first time that Sinwar, who had been hiding underground for a year, met the IDF (army) forces in Gaza and this is also the moment when he was eliminated," Hagari said on Saturday.

"Sinwar lived and behaved like a wanted terrorist."

The Hamas leader, who just months ago replaced his slain predecessor Ismail Haniyeh, had not been seen in public throughout the war.