Spokesmen for the Eritrean migrant population in Israel on Sunday denounced Israel’s policy of providing voluntary deportation forms for prisoners to sign.

“There is no such thing as voluntary return to the most brutal dictatorship in the world,” spokesman Gabriel Takla told reporters at a press conference, Walla reported. “Stop sending people back to Eritrea.”

Eritreans make up more than 60 percent of the more than 60,000 illegal African migrants who are believed to be in Israel, according to Haaretz.

As a signatory of the United Nations Convention Relating to the Status of Refugees, Israel cannot deport asylum seekers if they face danger in their country of origin. Israel grants Eritreans collective protection, but does not recognize them as refugees.

In February, a group of some 25 Eritrean migrants said they were pressured by Israeli immigration officials to sign a declaration saying they would agree to be deported to Uganda and then discovered that they were scheduled to fly to Eritrea, human rights group Hotline for Migrant Workers charged. The Eritreans refused to get on the plane.

Asylum seekers who return to Eritrea are in danger of persecution or even death at the hands of the Eritrean regime, rights groups say.

Israel has been searching for ways to deal with the growing number of African migrants entering its territory, and has built a wall on its southern border with Egypt. The presence of thousands of African migrants has led to tensions in Tel Aviv, including a violent protest in May 2012 that saw a mob vandalize African stores and smash the windows of a car with African passengers. One woman posed for a newspaper photographer wearing a white tank-top on which she had written the words, “Death to the Sudanese.”

That followed a firebomb attack on a Tel Aviv apartment housing migrants in early May, which followed a similar attack against a kindergarten for migrant children in late April. No one was hurt in those incidents.

Residents of the working-class Tel Aviv neighborhoods where many migrants have clustered described a growing threat of street crime as a result of the ballooning migrant influx, including two rape incidents in the weeks before the 2012 protests.

The first of the two rapes took place in a dark Tel Aviv courtyard on the night of April 25, and the second in a parking garage on May 14. Three young Eritreans, one of them a 14-year-old, were arrested in the first incident, and four in the second. In both cases the victims were also robbed.

These incidents reflected what police said was a rise of more than 50 percent in crime linked to African migrants in 2011.

Matti Friedman contributed to this report.