Tel Aviv - Sitting in his sparsely furnished flat in Tel Aviv, Fikre Mariam lowers his eyes and recounts watching footage of his cousin - a fellow Eritrean asylum seeker - beheaded by jihadists in Libya."It was horrible. I've never seen anything like it in my life," says Mariam, one of tens of thousands of African migrants who has sought asylum in Israel."Those people are not human beings - it's pure terrorism to commit and film atrocities like that."Mariam's cousin, 30-year-old Tesfay Kidane, was among a group of at least 28 African Christians killed in the graphic video released on April 19 by the Islamic State group in Libya.Sixteen of the victims were shot in the head while the rest, including Kidane, were beheaded.The video said the victims were Ethiopians, but Kidane and two others have since been identified as Eritreans who were reportedly trying to reach Europe by sea through Libya after being rejected for asylum in Israel.Their deaths have thrown the spotlight on the Jewish state's controversial immigration policies, which rights groups say have seen thousands of African asylum seekers coerced into "voluntary" departures.Kidane's friends and family only learned of his death after the video surfaced, when relatives and a Tel Aviv-based immigrant assistance group identified him and the other two Eritreans."It has given me nightmares," says Kidsti Ghezie, another cousin living in the same flat in southern Tel Aviv, where the walls are decorated with Christian icons and images."I saw pictures of him sitting in an orange jumpsuit. I didn't want to believe it was him," she says, referring to the clothing ISIS routinely forces its captives to wear in execution-style videos.No hope of asylumKidane crossed the border into Israel from Egypt in 2007, joining an estimated 48 000 illegal migrants in Israel from Africa, most of them Eritrean and Sudanese.He worked at menial jobs before eventually being detained and sent last year to the Holot detention centre in the southern Negev desert - a remote "open" facility that has a night-time curfew.More than 2 000 African migrants are housed in the sprawling complex, where they can be held for up to 20 months under Israeli law.Once in detention, they face either "voluntary" departure from Israel to a third country, usually Uganda or Rwanda, or transfer to the nearby Saharonim prison.Despite hardships in their home countries, few have any hope of being granted asylum.Of an estimated 30 000 Eritreans who have arrived in Israel in recent years, only four have been given official refugee status, according to rights groups such as the Hotline for Refugees and Migrants.It is not clear when exactly Kidane left Israel, but family members say that after being turned away in Uganda he arrived in Sudan, then travelled to Libya hoping to be smuggled into Europe.Contacted by AFP, the interior ministry refused to comment on Kidane's case or the issue of asylum seekers.Meseret Fisahaie, an Israeli-born relative of Kidane who works for HRM - which had the grim task of announcing Kidane was dead - says she tried to convince him not to leave Israel."Before he left he told me he was thinking about going to a third country, after the interior ministry told him he could get refugee status in Uganda or Rwanda," she says."I told him I had a bad feeling about it, but he just laughed and said: 'What do you think will happen to me?'"'Like living in a prison'At Holot, detainees who knew Kidane say he felt he had no choice but to go."It's like living in a prison," says Aman Beyene, standing outside Holot's main gate and squinting as a desert storm kicks up dust and sand."[Kidane] gave up - he got depressed and decided to leave."Beyene says that after seeing the video of the ISIS killings, he is more afraid of leaving Israel than of living in detention."I'd choose imprisonment here over departure," he says.At the camp, Sudanese and Eritrean migrants wander aimlessly, drinking beer and smoking around the ashes of campfires burned during the night.They are allowed out during the day, but with an evening curfew and the nearest major city an hour's drive away, many feel trapped.In a report last month, HRM said Israel is using "a myriad of methods" - including detention at Holot and withholding refugee status - to "coerce asylum seekers to leave".It rejected claims that asylum seekers are departing voluntarily, saying there is no real choice between "leaving Israel and prolonged detention".Still, authorities insist their policies are humane.Interior Minister Gilad Erdan said last month the goal was to "encourage infiltrators to leave Israel in a safe and dignified way."