A 19-year-old man has been arrested in connection with a brutal and apparently unprovoked attack against four young Palestinians in downtown Jerusalem early Friday morning. The attack was allegedly perpetrated by dozens of Jewish teens, whom eyewitnesses say were wandering around the area "searching" for Arabs to beat up.

The suspect in custody, a Jewish resident of Jerusalem, aged about 19, was arrested on Saturday, according to police. The suspect is to be brought before a judge today for a detention hearing.

Authorities say additional arrests can be expected. Acting Jerusalem police chief Maj. Gen. Menachem Yitzhaki has appointed a special team to investigate the incident.

Several organizations associated with the Tag Me'ir anti-racist coalition demonstrated in Jerusalem last night to protest the attack.

Jamal Julani, one of the victims of the attack, remains in serious condition, according to authorities. Julani, 17, from Jerusalem's Ras al Amud neighborhood, was admitted to the intensive care unit at Hadassah University Hospital, Ein Karem, in critical condition and is on a respirator. His mother told Haaretz that he has woken from his coma but is very confused, did not remember the assault and did not understand why he was in the hospital.

The other three victims, who were not seriously injured, are cousins of Jamal's.

"There were four of us," one of the cousins, Mohammed Mujahad, said on Saturday, recalling what happened after he and his three cousins reached the Zion Square area of Jerusalem after midnight Thursday. "We were walking and suddenly maybe 50 Jews came toward us shouting, 'Arabs Arabs.' I don't understand what they said. They weren't calling us. They were just generally shouting."

According to another eyewitness, the group of teenagers appeared to be hunting for Arab victims, calling out "Death to Arabs" and other anti-Arab slurs.

"We walked slowly, so there wouldn't be trouble," related Nuaman Julani, another of Jamal's cousins. "Suddenly one of them said to Jamal, 'What are you doing, you son of a bitch?' Jamal tried to flee, but [the attacker] whacked him in the chest and [Jamal] fell with his head on the floor."

The incident was brief, according to Mujahad and Nuaman Julani. One of the cousins says he saw a few of the attackers hitting and kicking Jamal as he lay on the ground. Both cousins noted that police officers quickly arrived on the scene, after which all the perpetrators dispersed. Jamal lost consciousness, presumably when his head struck the ground.

"They told me he died. His whole face was blue," Julani said. When paramedics from Magen David Adom and the volunteer EMS organization Ichud Hatzalah arrived on the scene, Jamal was not breathing and had no pulse. They performed resuscitation measures for several minutes before taking him to the hospital.

Writing on her Facebook page, one eyewitness decribed the attack as a "lynching": "It's late at night, and I can't sleep," she wrote. "My eyes have been filled with tears for a good few hours now and my stomach is turning inside out with the question of the loss of humanity, the image of God in mankind, a loss that I am not willing to accept."

"But today I saw a lynching with my own eyes, in Zion Square, the center of Jerusalem," she wrote, adding, "Dozens (!! ) of youths ran and gathered and started to really beat to death three [sic] Arab youths who were walking quietly on Ben Yehuda Street.

"When one of the Palestinians fell to the floor, they continued to kick him in the head, he lost consciousness, his eyes rolled, his angled head twitched, and then [the perpetrators] fled and the rest gathered in a circle, with some still shouting with hate in their eyes. When we returned to the area ... two teens stood there who did not understand why we wanted to give a bottle of water to the cousin of the victim. 'He is an Arab, and they don't need to walk around in the center of the city, and they deserve it, because this way they will finally be afraid.' ... Children aged 15-18 are killing a child their own age with their own hands. Really with their own hands. Children whose hearts were unmoved when they beat to death a boy their age who lay writhing on the floor."