The anguish over some 200 people kidnapped by Hamas in its brutal attack on Israel is in the spotlight - but Hamas has been holding at least two Israelis for years.
Very little has been heard about Ethiopian-Israeli Avera Mengistu and Bedouin Arab Israeli Hisham al-Sayed, seized in 2014 and 2015 respectively.
The relatives of two dead Israeli soldiers are also tormented by the fact that Hamas has been holding their remains in Gaza since 2014. Hadar Goldin and Oron Shaul were killed during a war between Israel and Hamas that year.
Hamas - backed by Iran and regarded by Western nations as a terrorist group - has previously demanded a high price for releasing captive Israelis. They are used as Hamas bargaining chips.
Aviram Shaul, brother of Oron, says that for nearly 10 years his family has had no news from Hamas about where it is keeping Oron's body, no sign that Oron will be returned.
In 2014 the army found Oron's helmet and bulletproof vest in a Hamas tunnel in Gaza. But since then, Aviram told the BBC, "I feel Israelis forgot about them [the two dead soldiers]".
"Now is a good chance to bring my brother back, because we're talking about 200 families with relatives held hostage in Gaza. The government did not do enough to bring my brother back, but now they have to make a big effort."
He said now "Israel needs to do a humanitarian deal to get the hostages out". "If Hamas wants electricity, water, they must give us the hostages and soldiers' bodies and Israel does nothing if they don't want to."
After secret negotiations in 2011 Israel got the abducted soldier Gilad Shalit back - but in exchange for 1,027 Palestinian prisoners held in its jails.
Israel is now determined to wipe out Hamas and is inflicting huge casualties and damage on Gaza with air strikes. So any new prisoner swap would be both difficult and controversial. As the Gaza death toll mounts, Palestinian fury at Israel intensifies.
Hagai Hadas, formerly an Israeli military commander and Mossad intelligence officer, played a key role in negotiating Shalit's release.
He told the BBC that such prisoner deals with Palestinian kidnappers were "a political issue" and in the current emergency, with so much Israeli anger directed at Hamas, "it's not going to happen, it's impossible".
He stressed that the controversial Shalit swap was possible politically for Prime Minister Benjamin Netanyahu at the time - he felt secure enough - and the deal had been finalised two years before Shalit's release.
"Now I think the price won't be Hamas prisoners - it's to be paid using different tools," Mr Hadas said.
He stressed that Israel now had various options: direct military rescues if the intelligence on the captives' locations was precise; use of "economic assets" - that is, payment; humanitarian options; or "to let Hamas leaders escape from Gaza, say to Qatar".
On the latter option, he said, "you have to put them under stress, give them the idea that to save their lives they can make such a deal".
"I believe the majority [of hostages] are in Hamas hands, but several are not. I'm almost sure that Israel is making every effort to locate them and try to bring them out by military means."
He said that "even in a full-scale war in Gaza, Israel will push for a deal to get the hostages released, it will try to the last second to find a solution". "We value life and are willing to pay for life."
The two Israeli civilian hostages held by Hamas since 2014 "were not kidnapped", Mr Hadas said, but "they went to Gaza, they were not mentally fit". "It's a big difference - we've had nothing similar to what we experienced on 7 October," he said, referring to the massacre by Hamas.
Hamas claims that Avera Mengistu and Hisham al-Sayed are soldiers, but official Israeli documents seen by Human Rights Watch show that both are civilians who were exempted from military service.
Tila Fenta has led a campaign to get Avera released and feels let down by the Israeli state - though she says the international spotlight on Gaza hostages now might help her cause.
"I want to believe that the chances for Avera have improved, but I say that in all sorrow," she told the BBC. She stressed that "we are still in shock - all Israelis are" since the Hamas attack and mass hostage-taking that killed about 1,400 Israelis.
She said the campaigners felt "devastated" by Israel's failure for all these years to secure the return of Avera and Hisham.
"They're not soldiers, both are sick - they have mental issues - and Hamas captured them against all humanity," she said.
She linked the lack of progress over Avera and Hisham to their disadvantaged background and discrimination in Israeli society towards Ethiopian Jews and Bedouin Arabs.
"I think Avera is a man who society doesn't like so much, because of his colour, mental illness problem and having grown up in a poor area of Ashkelon.
"I think all this made him not wanted in society. If he was a bit brighter, or from a good area the treatment would be different. I know this isn't the time to say something wrong about my country, but the truth must be told." She said big human rights organisations should also have done more. "The same goes for the Bedouin - both are disadvantaged."
A third young Israeli citizen, Jumaa Abu Ghanima, is believed to have crossed into Gaza in 2016 and is still missing. A Bedouin Arab, like Hisham, he may be in Hamas hands, but there is no confirmation.
Before illegally entering the Gaza Strip, both Avera and Hisham had gone missing repeatedly, and had had psychiatric treatment, Human Rights Watch research shows.
In January Hamas released a short undated video clip of a man who mumbled in Hebrew: "I am the captive Avera Mengistu. For how much longer will I remain in captivity with my friends." The Mengistu family confirmed his identity, the Free Avera campaign told the BBC.
Prime Minister Netanyahu told Avera's mother Agurnesh that the government had "confirmation" that her son was still alive. He said Israel "does not stop its efforts to return Avera Mengistu and the rest of our captives and missing persons".
In June 2022 Hamas released a video showing Hisham al-Sayed in captivity. Hisham's father Shaaban al-Sayed confirmed his identity.
Hamas said only that Hisham's health had deteriorated - no more details were given. He could be seen lying attached to a ventilator beside what appeared to be his Israeli-issued ID card.
Tzur Goldin, brother of the late Hadar Goldin, whose remains are still in Gaza, has urged Israel to adopt a clear policy to tackle Hamas kidnapping.
"Kidnapping is directed against families and is designed to break up societies. We have become accustomed to a certain security situation, to a certain conduct. We have become accustomed to it being convenient for the captives and the missing to be on the sidelines," he said, quoted by Israel National News - Arutz Sheva.
"There is a round of fighting, followed by silence, followed by another round and more silence."
Freeing any of the Hamas hostages looks likely to be a messy, controversial affair. "It's a dilemma everywhere in doing deals with terrorists," Hagai Hadas told the BBC. "You have contradictory options, they can be good or bad."