Israel Gaza: Checking Israel's claim to have killed 10,000 Hamas fighters

The Israeli military says it has killed more than 10,000 fighters in its air strikes and ground operations in response to the Hamas attack which killed about 1,200 people.

But there are concerns about whether it is able to separate fighters from ordinary civilians. President Joe Biden said in December that Israel had the support of the world as well as the US, but "they're starting to lose that support by the indiscriminate bombing that takes place".

The Israel Defense Forces (IDF) have consistently defended their tactics, stressing that they are trying to be precise in their targeting of Hamas fighters and infrastructure, while seeking to minimise civilian deaths.

Hamas does not provide any figures for its military fatalities. The Reuters news agency reported that an official had admitted 6,000 fighters had been killed, but Hamas denied this figure to the BBC.

The toll of at least 30,035 killed, from Gaza's Hamas-run health ministry, has previously been described as trustworthy by the World Health Organization's (WHO) regional emergency director Richard Brennan.

The WHO says the ministry has "good capacity in data collection" and its previous reporting has been credible and "well developed".

But its overall tally of those killed does not distinguish between civilians and combatants.

The Gaza authorities' last demographic breakdown from 29 February indicated more than 70% of those killed had been women and children.

So, with the figures suggesting less than 30% of those killed were men - some of whom are likely to be over fighting age - experts have raised questions about how Israel arrived at its claim of killing 10,000 fighters.

BBC Verify has repeatedly asked the IDF for the detail of its methodology for counting Hamas fighter deaths but they have not responded.

The BBC tried to piece together a fuller picture through claims and videos published by Israel.

References to the numbers of fighters killed in these announcements are more sporadic and approximate than the Hamas-run health ministry's regular updates on fatalities.

One IDF estimate before the war suggested Hamas had about 30,000 fighters in Gaza.

In December, it described an assessment that it was killing two civilians for every Hamas fighter as "tremendously positive", given the challenges it faced on the battlefield.

On 29 December, IDF spokesman Major Doron Spielman told Sky News Australia that 8,000 Hamas fighters had been killed, saying the figure was based on intelligence, interrogations and examination of satellite photographs.

In mid-January, Prime Minister Benjamin Netanyahu claimed Israel had "destroyed" two-thirds of Hamas fighting regiments in Gaza.

On 19 February, the Times of Israel reported the IDF as saying 12,000 fighters had been killed. We put that figure to the IDF who, in two separate responses to us, said the figure is "approximately 10,000" and "more than 10,000".

The Israeli embassy in the UK told us they think the total number of Hamas fighters killed is "between 10,000 and 12,000".

But they said it was hard to distinguish between civilians and combatants as many of them are not wearing military uniform and Hamas also has fighters who are aged 16 and 17.

Other factors cited by experts as obstacles to counting combatant casualties include Hamas operating in tunnels.

BBC Verify reviewed all 280 videos posted to the IDF YouTube channel from 7 October up to 27 February and found that very few contained visual evidence of fighters being killed.

Of these just one - posted on 14 December - purports to show dead bodies of fighters. A handful of other videos appear to show fighters being shot at.

We also attempted to count the number of individual claims of Hamas fighters killed on the IDF's official Telegram channel. We found 160 posts claiming to have killed a specific number of fighters, for a total of 714 fatalities.

But there were also 247 references which used terms such as "several", "dozens" or "hundreds" killed, making a meaningful overall tally impossible.

Since the beginning of the IDF incursion into Gaza, the military has accused Hamas of using the civilian population as human shields.

But some experts are concerned that the IDF might be counting some non-combatants as fighters merely because they are part of the Hamas-run territory's administration.

Andreas Krieg, a senior lecturer in security studies at Kings College London, said: "Israel takes a very broad approach to 'Hamas membership', which includes any affiliation with the organisation, including civil servants or administrators."

The fatality data for the current conflict from the Gaza health ministry shows a sharp increase in the proportion of women and children among the dead compared with previous wars.

This "indicates a much higher civilian death rate," according to Rachel Taylor, the executive director of the Every Casualty Counts organisation, a UK-based organisation that aims to record victims of violent conflicts.

Nearly half of Gaza's population is under 18 and about 44% of the fatalities of war are also children, according to the Gaza authorities' 29 February demographic data. Ms Taylor said the fact that the deaths closely track the demographics of the general population "indicates indiscriminate killing".

"In contrast, in 2014 there was a fairly high percentage of 'fighting age' men among the dead, but this is much less evident today," she said.

The pace of killing appears, on the face of it, to have slowed down, from about 330 deaths a day in the first month of the conflict to approximately 110 deaths a day over the past month.

But some experts told the BBC that the real scale of those killed by the Israeli offensive is likely to be significantly higher as many hospitals, where deaths are usually recorded, are no longer operating.

These figures also only include deaths from military attacks, according to the health ministry's spokesman, and not starvation or disease, which are increasingly concerning international aid organisations.

B'tselem, a Jerusalem-based human rights organisation, said the current war is far deadlier than previous conflicts between Israel and Gaza.

Spokesperson Dror Sadot said: "These are numbers that we never saw in previous wars and strikes in Gaza or the other territories."

-bbc