"During a special unit's operations... a video was discovered in a tunnel from a security camera installed there. The footage shows leader of Hamas and mass murderer, Yahya Sinwar, fleeing with his children and one of his wives," army spokesman Daniel Hagari said at a briefing.

"This is how he escaped with his family from an underground tunnel to a secured complex he had built in advance," Hagari said.

"This video of Sinwar is the result of our hunt. This hunt will not stop until we have captured him dead or alive."

AFP was unable to independently verify the authenticity of the video.

Hagari said the video had been filmed on October 10, three days after Hamas carried out an attack on Israeli that resulted in the deaths of about 1,160 people, mostly civilians, according to an AFP tally based on Israeli figures.

In response, Israel vowed to eliminate Hamas and launched a military campaign in Gaza that has killed at least 28,473 people, mostly women and children, according to the health ministry in the Hamas-run territory.

Israel accuses Sinwar of masterminding the October 7 attack that triggered the war, now in its fifth month.

The images released on Tuesday are said to be the first of him since the war broke out.

The black and white footage shows a young man leading a woman, three children and another man, who the army said was Sinwar, from one end of a tunnel to another.