TEL AVIV, Israel — “Sometimes we sleep in there,” says Zarjan Hussein Zarjan, jerking his head toward the colorful plastic slide. “It keeps the rain off.”

At night, he says, he and a few hundred other refugees — mostly young men — gather here in Levinsky Park, a grassy open space in south Tel Aviv. Tents and blankets appear, some of them stashed under the slide during the day.

Zarjan is one of more than 50,000 thousand Sudanese and Eritrean refugees living a precarious existence in Israel. They face a choice between detention, a life on the run, or returning to a country of origin that many fled in fear for their lives.

The presence of Sub Saharan African refugees in Israel is a relatively new phenomenon. It wasn’t until 2005 that people began coming in large numbers.

In 2012 Israel erected a wall that halted the flow of refugees across its borders. But it's been unclear what will happen to the 37,000 Eritreans and 14,000 Sudanese already in Israel at that time.

The fear in some quarters of Israel is that a large number of non-Jewish residents arriving threatens its Jewish character.

Many people — including mainstream politicians — use the Hebrew word for “infiltrators” to refer to refugees and asylum seekers. In May 2012 recently re-elected Prime Minister Benjamin Netanyahu called them “a threat to the social fabric of our society, our national security, our national identity … and … our existence as a Jewish and democratic state.” A parliamentarian called them “a cancer in our body.”

It's not only refugees that have faced discrimination in Israeli society. This week a protest of thousands of Ethiopian Israelis against police brutality was met with...police brutality. Officers shot tear gas and stun guns into the crowd and reportedly injured 15 people.

Zarjan never intended to end up in Israel. Six months shy of his college graduation in aviation sciences, he fled Sudan for Egypt. Originally Darfuri, an ethnic minority in Sudan, Zarjan was persecuted in his home country for his political beliefs. But in 2011, Egypt was in the midst of its own turmoil that toppled longtime dictator Hosni Mubarak from power, and Zarjan decided to go somewhere where he felt safer.

“When I arrived in Israel it wasn’t how I thought it would be. My friend said you could study at the university here but when I arrived I saw that he was working in construction.”

Zarjan now takes day work whenever he can get it. At least life in the park is better than life in captivity.

When Zarjan first arrived he was picked up at the border and taken to a detention center in the Negev desert. After a month, with no money and little but the clothes he was wearing, he was given a one-way bus ticket to Tel Aviv.

Refugees like Zarjan, are not allowed to work officially, and every two months must renew their temporary residency papers until one day, usually about four years into their stay, they are told to report to Holot, a detention center in the desert near the Egyptian border.

Zarjan fears that any day now he will get such a notice.

African asylum seekers awake ready for a second day of protest outside the Holot detention centre where hundreds of migrants are being held February 18, 2014 in the southern Negev desert of Israel. More than 50,000 illegal African migrants are seeking asylum after escaping war and government repression in their native lands.

‘The Zionist enemy’

Once at Holot refugees face a stark choice: indefinite detention in Israel or a return to countries where many fear for their lives. While the Israeli authorities call Holot a “residency center,” it's guarded by Israel’s prison service, and residents are required to sleep there every night.

Around 7,000 Sudanese have gone back to Sudan, rather than face detention, according to Human Rights Watch. They do so at great risk because Sudan considers Israel an enemy state.

“Netanyahu has given us a choice, either Holot or back to Sudan,” says Zarjan. “But in Sudan they consider you a Zionist enemy,” he says of those who have spent time in Israel.

Sudanese law punishes anyone who sets foot on enemy soil with up to 10 years in jail. Some Sudanese have been jailed, tortured and charged with treason upon their return.

It’s not just in Sudan where returning migrants face danger. On Tuesday, an Israeli NGO called Hotline for Refugees and Migrants identified three of the victims whose purported beheadings were shown in a recent Islamic State video as Eritreans who left Israel in 2014.

A relative of one of the men told an Israeli newspaper that he had left Israel for Uganda or Rwandain the past year.

"He had been in Israel since the end of 2007. He decided to go back after the [Israeli] Ministry of Interior told him he would be better off,” the relative told Haaretz.

The same relative said the man had tried to reach Europe by boat — traveling first to Rwanda, then Libya. The attempt was unsuccessful, and upon his return to Libya he was likely taken by the Islamic State.

Israel cannot deport most Eritreans because of the risk of serious harm upon their return. In some cases, they have instead been deported to third countries where they are not guaranteed protection. In desperation some head for North Africa, and from there, to Europe.

Human Rights Watch has argued that refugee returns to their home countries under these conditions should not be considered voluntary and should instead be seen as "refoulement," defined as the “expulsion of persons who have the right to be recognized as refugees” — and therefore a violation of international law.

Israeli policemen and immigration officers arrest African asylum seekers after spending the last two days protesting in an outdoor camp near the Nitzana border crossing with Egypt in the Negev Desert on June 29, 2014.

A poisonous atmosphere

The harsh policy toward migrants in Israel is reflected in comments from the country’s political leaders.

“None of them like us, whether left or right,” says Khalid Adam, 26, also from Darfur.

Public figures as well as citizens routinely say that asylum seekers are not “real” refugees, but economic migrants.

Many seeking asylum in Israel have already faced unimaginable horrors before arriving. An estimated 7,000 of the refugees in Israel spent time in camps in Egypt’s Sinai, where traffickers detained and tortured them until relatives paid heavy ransoms.

And yet, as of mid-August 2014, 99.9 percent of Eritrean and 100 percent of Sudanese asylum claims in Israel were rejected according to Human Rights Watch. Globally an average of 83 percent of Eritrean asylum seekers and 67 percent of Sudanese were granted protection in host countries.

Israeli officials, for their part, outright deny that these people are refugees. "First, they are not refugees — if they were recognized as refugees they would have gotten a permit, and not been sent to Holot," says Sabin Hadad, a spokesperson for the Population and Migration Authority in the Ministry of the Interior.

Israel, more than most other countries in the world, has the infrastructure for large-scale immigration. It has been welcoming newly naturalized Jews from around the world for the entirety of its existence. But refugees receive no such benefits.

“Some right-wing people really believe they are protecting the Jewish state,” says Elisheva Milikowsky, director of the Migrant Workers, Refugees and Asylum Seekers Department at Physicians for Human Rights (PHR) in Israel. “They push the idea that they are not ‘real refugees’ but came to improve their lives.”

She says that when she tells people in Israel she works with refugees, they often ask her why she would want to help those “infiltrators” and “criminals.”

But the lives of refugees and asylum seekers in Israel may be about to get even worse. De facto prison conditions may soon be replaced with actual jail time.

Following a court decision at the end of March, Eritreans and Sudanese in Holot are being told that authorities can now order them to a third country — likely Rwanda or Uganda — and if they refuse, they can be detained in prison for non-cooperation with deportation procedures.

In the absence of a formal agreement between Israel and the third countries, there’s no guarantee that asylum seekers won’t be sent back to their countries of origin, anyway.

But with no other options, people like Zarjan take that chance.

“I just want to get out and study. I don’t want to stay here.”