The security men in khaki vests had the Arab youth pinned to the sidewalk, twisting one of his arms behind him as he screamed that he was in pain.

It was a late summer night on Jerusalem's Jaffa Road, nearly a week after the pummeling of a young Arab by a group of Jewish teenagers a few blocks away in Zion Square, an attack police called an attempted lynch.

This time it was the security guards assigned to Jerusalem’s light rail system who were holding an Arab down, saying that he had resisted a security check before boarding the train. The youth, who was held on the pavement for more than half an hour as Israelis and tourists strolled wordlessly by, said from his lock-hold that when he objected to a search, he was wrestled to the ground though he had offered no physical resistance.

An Arab man from the Old City was outraged by the sight of the youth being held so long on the sidewalk, in full view off passing pedestrians.

“Is this how you treat a human being in front of everybody like that?” he thundered at the security men. “What kind of democracy is this?”  A Jewish onlooker said the security men were doing the right thing, telling me “they would do the same to you if you refused to be checked.”

Eventually, police officers showed up, handcuffed the young man, and took him away. The onlookers dispersed, and the street slipped back into its normal rhythm – a last blast of summer downtown, with people jamming cafes, restaurants and pubs late into the night. 

Under the throbbing nightlife, however, a menacing current has erupted in episodes of violence, sometimes fueled by alcohol and often stoked by the festering conflict with the Palestinians.

In the noisy alley outside Zolly’s pub, where he works, Ahmad Kamal, from the East Jerusalem neighborhood of Shuafat, said that a day earlier he had been cursed and beaten by a group of Jewish youths who assaulted him on his way home from work in the wee hours of the morning. Complaints about such attacks to the police, he said, were usually not followed up.

Yasser Julani, who works at a neighboring restaurant, showed a scar on his neck he said was caused when he was cut by a bottle fragment in an assault by Jewish youths. “There’s racism between Jews and Arabs because of the situation,” he said. “But the Jews I work with are like brothers.” On the night of the beating in Zion Square, he recalled, the mob, which chanted “Death to Arabs,” was driven away from the area of his restaurant by both Arab and Jewish workers.

Ahmad Shweiki from Silwan, who was walking back from a night downtown with a friend, said he wasn’t afraid to go out, but sometimes carried a personal tear-gas canister in case of trouble. 

Yossi Milman, a young Israeli who said he was a regular in the bar zone near Zion Square, said the violence was often provoked by what he described as indecent passes by Arab youths at Israeli girls. “They see things here they don’t see in their villages, and they have a hard time controlling themselves,” he said. “They harass girls, touching them, and people come to help.”

A similar motive was cited in the recent beating in Zion Square, which police said followed a complaint by a Jewish girl that she had been harassed by an Arab.

Bur the violence is not only between Arabs and Jews. Several weeks ago, a young Israeli was badly beaten by other Israelis when he came to the aid of his brother, who was jumped by a group after he objected to their attempt to board a taxi ahead of him.

The tensions have not deterred Palestinians from East Jerusalem and those with permits from the West Bank from visiting the downtown area in the western part of the city. A few blocks away from the incident near the light rail station, Ismail Abu Ajra from Bethlehem sat on a bench with friends after an evening out and some shopping.  They were enjoying a rare visit thanks to Israeli entry permits issued in large numbers this year for the Muslim holy month of Ramadan. “It’s more alive here,” he said. 

Down the street, at Zion Square, a group strummed electric guitars. They were black-garbed ultra-Orthodox Jews, newly religious men who had clearly played much rock-and-roll in a previous life. One bearded player with sunglasses and sidecurls picked a tune, a cigarette wedged between his fingers sliding across the frets. The song was the Pink Floyd hit: “Wish you were here.”