Mariam - that is not her real name - knows she is being held in the Sinai, but can't be exactly sure where. The house is large, she says, and possibly purpose-built: there are no floorboards or any furniture.

The filthy blankets crawling with lice are far too thin to protect Mariam and her three- year-old daughter from the cold. The threadbare fabric is spattered with dark rust-colored stains: dried blood belonging to Mariam and the many other hostages who were shackled to the bare floor before she was forced to take their place.

"Everyone is sick, we all have diarrhoea," she whispers. She is speaking down a mobile phone. Their captors permit the device so that she and the other hostages can call friends and relatives and beg them to pay the ransom.

Torture 'every night'

The mobile phone signal is faint, but Mariam is too afraid to speak up. One of the captors, a Bedouin from the Rashida tribe, is standing outside the door and she is terrified he will hear her.

He and four other men torture them every night and threaten to kill her child, she says.

The hostages are shackled together in groups of four and five. Salome, again not his real name, says the captors make them lie on the floor naked and then burn their backs with melted plastic bags.

A friend of Mariam's sister has posted a desperate plea on Facebook, asking her friends to help her raise the $27,000 ( 20,000 euros) needed to secure Marian and her daughter's release. Mariam's mother is dead. Her father is a farmer in a small village in Eritrea and it would take him a lifetime to pay the ransom.

Mariam's husband is living in a refugee camp in Ethiopia. The young couple had decided to flee Eritrea. They had heard of the shoot-to-kill border policy, but not of the abductions. Nevertheless, they were desperate to leave.

Sold into captivity

In its World Report 2012, the rights group Human Rights Watch says Eritrea's citizens "remain victimized by one of the world's most repressive governments. They suffer arbitrary and indefinite detention; torture;inhumane conditions of confinement; restrictions on freedom of speech, movement and belief; and indefinite conscription and forced labor in national service."

Mariam had paid a trafficker to take her and her daughter from their small village to neighboring Sudan. From there she had wanted to make her way to Ethiopia to join her husband. "As soon as we arrived in Sudan, one of the traffickers told us he would take us to the nearest city and the refugee camp," she says. Instead, the Sudanese traffickers forced them into a car at gunpoint and handed them over to their Egyptian captors. Both were from the Rashia tribe. Salome tells of his experiences: "When we had made it to the border and saw the border guards, we thought we were safe." He was wrong. Corrupt Sudanese border guards had sold him on to the traffickers.

Philippa Candler is Head of Protection in Sudan at the UN refugee agency, the UNHCR. She says some 2,000 refugees arrive at the Shagarab processing camp inside the Sudanese border every month. Most are from neighboring Eritrea where many have fled compulsory military service. Almost 80 percent leave Shagarab within two or three months. "Most of them move on because they have been contacted by traffickers or smugglers," Candler says.

The Sudanese government does not allow refugees to move freely in the country so traffickers are the only option for those wanting to join friends and relatives in Europe or elsewhere.

Candler says that Eritreans, Ethiopians and Somalians are being held hostage in Sudan and the Sinai desert.

A priority in relations with Cairo

Swedish-Eritrean journalist Meron Estefanos believes the hostages are victims of an international smuggling network. Relatives hand over money to middlemen operating in countries with big Eritrean diasporas, including Switzerland, Sweden, Israel and the United States. She is convinced the Egyptian authorities have given their tacit approval. Estefanos puts the number of hostages currently being held in Sinai at between 300 and 500.

Mariam's kidnappers have given relatives a deadline to pay the ransom, then they are threatening to kill her and her daughter.

In a recent resolution the European parliament called on EU foreign policy chief Catherine Ashton to make the issue of human trafficking in Sinai a priority in ties with Cairo.

Author: Naomi Conrad/Mark Caldwell
Editor: Susan Houlton / rm