Hundreds of African refugees are being held hostage in the Sinai desert of Egypt by smugglers demanding up to $40,000 (£25,000) each for their release, human rights workers have warned.
A brutal trafficking industry has flourished over the past year in which Bedouin gangs, emboldened by their apparent impunity, extort higher and higher prices for kidnapped migrants.
Most of the hostages are Eritrean and Sudanese asylum seekers who paid $3,000 each to the gangs to get them to the Israeli border. Instead, they are subjected to daily torture as their captors phone their relatives at home and abroad demanding huge sums to spare their lives.
Asmerom (not his real name) receives 10 calls a day from a childhood friend, who is among 30 women and 12 men from Eritrea held in one Sinai camp. She contacts him because, unlike her family, he lives in Israel and might have access to money. She tells him they are being starved, beaten and burned with electric cables.
The 19-year-old's captors initially demanded $40,000 for each of the 42 hostages but after three weeks, dropped the price to $30,000. The smugglers say Asmerom, 20, needs to get the money to their agent in Israel quickly or they will kill her.
"They call me when they are beating her. Her hands and feet are tied so they put the phone up to her mouth while she is screaming," said Asmeron, clutching his phone in his hands. He looked aghast when it rings.
"I don't understand them, they're speaking Arabic. Listen, she keeps crying: 'Help me, help me.' What can I do?"
Physicians for Human Rights (PHR), an Israeli NGO, say Asmerom has little choice but to try to raise the money. PHR runs a clinic in Jaffa, south of Tel Aviv, offering medical care to asylum seekers and foreign workers who, without official status in Israel, are ineligible for anything but emergency healthcare.
Every year several thousand Africans, most of them from Eritrea and Sudan, try to get into Israel – something the Israelis are eager to halt.
Over the past 18 months, PHR has interviewed 900 people who have been tortured in the Sinai, and have traced a human trafficking network that extends to the refugee camps in Sudan and Eritrea. The NGO knows of at least 350 people being held now.
Its clinic in Jaffa is familiar with the injuries inflicted by these gangs. Torture methods include pouring hot plastic on victim's body, electric shocks, rape – including penetration with objects – and branding with hot irons. If these methods fail to extort enough cash, survivors say the smugglers either kill their hostages or sell their organs.
"We have heard of mass graves of hundreds of people," said Shahar Shoham, who heads PHR research into the Sinai torture camps.
Mogos Redae, 33, was released last June after nine months. His family raised money to free him by selling their house and valuables. He is lucky to be alive.
His captors would apply electric shocks to him and his fellow hostages in front of young children, encouraging the toddlers to laugh as the victims screamed in agony. Three men held with him died as a result of the beatings, one while he was shackled to Redae.
"We fell asleep huddled together but when they tried to wake him, he was dead," said Redae. "They wrapped him in a bed sheet and threw him on the car, like garbage. They did this to me three times. They threw me to the car and then saw I was alive.
"Nobody stops you from calling whoever you want because they want the money. As long as the person you are calling is fruitful."
After three weeks of phone calls, Asmerom could no longer bear listening to his friend's screams. He turned off his phone and started trying to raise the money.
He contacted his friend's parents in Eritrea, who scrabbled to produce $17,000 by selling the family home. He has given all the money he can. So have his friends and even his employer – an elderly Israeli man he cares for three days a week. He now has $24,000, but it is not enough for the captors and he has exhausted all his options.
"I went to the police station in Jerusalem. I waited for five hours and I told them everything. They said come back when I've raised all the money. They didn't tell me how to do that. Frankly, they didn't seem to care," Asmerom said.
A spokesperson for the Israeli police said they were unable to comment on the case or any other without investigating each fully, while Israel's defence ministry said it would be inappropriate to comment on an internal Egyptian issue. A spokesperson for the Egyptian ministry of the interior claimed to have no information on trafficking or torture in the Sinai region.
But Shoham said: "We know the names of the smugglers and their locations. We have briefed the Egyptian embassy in Israel but so far the Egyptian authorities are not doing anything.
"It is the responsibility of the Egyptian government to stop the traffickers. It is also the responsibility of Israel to protect the victims, but instead the ransoms are getting higher and the stories of torture are getting worse."