A 15-year-old girl was brutally raped, allegedly by Eritrean refugees, in south Tel Aviv last month while her boyfriend, also a minor, was forced to watch. The case was under a gag order until yesterday.

Three suspects have been arrested, all of whom match the DNA samples taken from the girl and the crime scene.

This was the first of three shocking rapes committed in Tel Aviv over the last few weeks. Last Friday, a woman was raped in front of her boyfriend in a Tel Aviv parking garage, and on Monday, another young woman was raped in a different parking garage. A Palestinian was arrested in the former case, while the four suspects arrested in the latter are also Eritreans. In all three cases, the victims were also robbed.

This first rape the just came to light took place on the evening of Independence Day. The two teens, both from north Tel Aviv, had gone to a nightclub near the city's central bus station, and were there until 4 A.M. Seeking privacy, they left and went into an courtyard on Shivat Zion Street.

Police say three Eritreans then entered the courtyard and two of them began beating up the boy while robbing him of his cell phone and a neck chain. The third allegedly pushed the girl against a wall and took her cell phone to keep her from calling for help.

Police say that after beating up the boy, one of the men raped the girl while the other two made her boyfriend watch. Then a second man decided to rape her as well.

Afterward, the suspects fled in the direction of the bus station.

The two teens walked to Salameh Street, where passersby summoned police and an ambulance. They were taken to the hospital, which did the routine tests for rape, including taking DNA samples.

Over the next several days, police questioned dozens of people in an effort to locate the perpetrators, but only on May 10 did someone finally give them the name of a possible suspect. Police say they located the man and found that his DNA matched the DNA left on the girl by one of the rapists. The suspect then led the police to the other two.

All three suspects are Eritreans. Two are 18 years old, one is 14. They arrived in Israel about a year and a half ago and have since been working odd jobs. One of them has reenacted the crime for the police, and all are slated to be indicted in the next few days.

According to statistics presented to the Knesset Committee on Foreign Workers by the police in March, there was a 54 percent increase in crime by African migrants last year, with the number of cases rising from 790 in 2010 to 1,223 in 2011. Police said that migrants from Eritrea account for 47 percent of all cases involving Africans and 24 percent of all cases involving foreigners, while Sudanese migrants account for 38 and 19 percent of such cases, respectively.

However, police acknowledged, they have no reliable data on the size of the foreign population, so it's impossible to tell whether migrants are disproportionately involved in crime.

While Africans account for almost two-thirds of migrant crime, police say this is partly because migrants from Eritrea and Sudan cannot work legally, and thus often steal to survive.

The highest concentration of migrants is in south Tel Aviv, near the central bus station. Official statistics say the city has some 20,000 migrants, but police believe the actual number exceeds 50,000, noting that official statistics count only migrants who passed through the Saharonim processing facility, and many do not.

Almost two-thirds of the crimes committed by African migrants in 2011 occurred in the Tel Aviv district. After Tel Aviv came the southern district, accounting for about 20 percent of crime by African migrants.

Yesterday, about 20 south Tel Aviv residents and activists demonstrated near the central bus station to protest the recent wave of violence by Sudanese and Eritrean migrants and demand their expulsion from Israel.

"I'm here to say this is a ticking bomb!" screamed Zahava Shirazi, 80, a disabled neighborhood resident. "Three times they've robbed me, and I can't run after them. This is the country I was born in; at age 16 I was recruited into the Palmach [a pre-state Zionist militia] and I fought for it. Now I don't have the strength to fight, and I'm afraid."