Tank tracks still fresh on his field in southern Gaza's coastal area of Al-Mawasi, Nedal Abu Jazar lamented the damage war has wrought on his trees and crops.

"Look at the destruction," the 39-year-old farmer told AFP, holding an uprooted tomato plant.

He pointed to his greenhouse's metal frame and its white plastic sheeting strewn across the plot, inside an area designated a humanitarian zone by the Israeli army.

"People were sitting peacefully on their farmland ... and suddenly tanks arrived and fired at us, and then there were (air) strikes."

The Hamas authorities in Gaza said an Israeli strike on Saturday on a UN-run school where thousands of displaced were sheltering killed 16 people.

Israel's military said its aircraft had targeted "terrorists" operating around the Al-Jawni school in Nuseirat, central Gaza.

The health ministry in the Hamas-run territory, which condemned the strike as an "odious massacre", said 50 injured were taken to hospital from the school.

Nine months after militants dragged Carmel Gat into Gaza, her family is part of a growing public and political campaign to press the Israeli government to use renewed negotiations with Hamas to end the nightmare of scores of remaining hostages like Gat.

Stop-start efforts to secure a ceasefire and a hostage release deal resumed on Friday when an Israeli negotiator met Qatari mediators. The new diplomacy has buoyed anguished hostage families.

"My hopes are up," Shay Dickmann, Gat's cousin, told AFP. "I'm feeling really positive about this deal."

Masoud Pezeshkian's victory in Iran's presidential elections has given a rare boost to efforts for scaling down years of tensions over Tehran's nuclear programme, even with no indication of any upcoming breakthrough in the crisis.

Pezeshkian's defeat of ultra-conservative Saeed Jalili, a former chief nuclear negotiator whose intransigence and style made him notorious among Western diplomats, is a relief for European governments as they seek to maintain dialogue on the issue.

Israel carried out deadly airstrikes in Gaza Saturday, including one on a UN-run school that killed 16 people according to the Hamas-run authorities, and as violence also gripped its northern border with Lebanon.

The fighting raged as diplomatic efforts to halt the war, which enters its tenth month on Sunday, continued with Israel saying Friday it would send a delegation next week to continue talks with Qatari mediators.

Iran's reformist candidate Masoud Pezeshkian, who advocates improved ties with the West, on Saturday won a runoff presidential election against ultraconservative Saeed Jalili, the interior ministry said.

The election came against a backdrop of heightened regional tensions because of the Gaza war, a dispute with the West over Iran's nuclear programme, and domestic discontent over the state of Iran's sanctions-hit economy.

Masoud Pezeshkian, Iran's only reformist candidate in the latest presidential election, has risen from relative obscurity to become the ninth president of the Islamic republic.

Pezeshkian, 69, won around 53.6 percent of the vote in a runoff election against the ultraconservative Saeed Jalili.

In the first round of Iran's snap elections on June 28, Pezeshkian led the polls against three other conservative figures, stunning supporters and rivals alike.

Iran's reformist candidate Masoud Pezeshkian on Saturday won a runoff presidential election against ultraconservative Saeed Jalili, the interior ministry said.

Pezeshkian received more than 16 million votes and Jalili more than 13 million out of about 30 million votes cast, electoral authority spokesman Mohsen Eslami said, adding that voter turnout stood at 49.8 percent.

The number of spoiled ballots was reported to be over 600,000.

Pezeshkian said the vote was the start of a "partnership" with the Iranian people.

Israel said Friday that "gaps" remained with Hamas on how to secure a Gaza ceasefire and hostage release but that it will send a delegation for fresh talks with Qatari mediators next week.

The statement from Prime Minister Benjamin Netanyahu's spokesman came after a delegation led by the head of Israel's Mossad intelligence agency, David Barnea, held a first round of talks with mediators in Doha on Friday.

"It was agreed that next week Israeli negotiators will travel to Doha to continue the talks. There are still gaps between the parties," the spokesman said in a statement.

Syrian President Bashar al-Assad's media adviser Luna al-Shibl died on Friday three days after being injured in a car crash, Assad's office announced.

"The presidency of the Syrian Arab Republic mourns the death of the adviser Luna al-Shibl, who passed away today after a serious car accident", it said in a statement.

"She served in recent years as a director of the political and media office of the presidency and then as a special adviser to the presidency," it added.