US intelligence chief Bill Burns and his Israeli counterpart David Barnea left Qatar late Saturday following talks on a Gaza truce and hostage release deal, a source briefed on the talks told AFP.

The CIA and Mossad chiefs "departed Doha to brief their respective teams back home on the latest round" of talks, the source said on condition of anonymity because of the sensitivity of the discussions.

"The talks focused on details and a ratio for the exchange of hostages and prisoners", the knowledgeable source added, explaining that "technical teams remain in Doha".

US, Qatari and Egyptian mediators have been engaged in weeks of behind-the-scenes talks in efforts to secure a second truce in the war between Israel and Hamas and the release of captives in exchange for Palestinian prisoners being held in Israeli jails.

Israel had said on Friday that the head of its spy agency was to return to Doha for his second trip in a week after talks were restarted following failed efforts to secure a truce before the Muslim holy month of Ramadan, which began last week.

The war began when Hamas launched an unprecedented attack from Gaza that left about 1,160 dead in Israel, mostly civilians, according to an AFP tally of official figures.

Israel's military has waged a retaliatory offensive against Hamas that has killed 32,226 people, most of them women and children, according to Gaza's health ministry.

Palestinian militants seized about 250 Israeli and foreign hostages during the October 7 attack on Israel, but dozens were released during a week-long truce in November.

Israel believes about 130 remain in Gaza, including 33 who are presumed dead -- eight soldiers and 25 civilians.