They stand like nude sentinels, hundreds of feet above the stone pedestrian streets of central Sao Paulo. The life-size human silhouettes appear tense, perched on the edges of high-rises, prepared to dive to their deaths below.

Passers-by point toward the sky, with perplexed expressions and mouths agape.

"What is that ... a man? No. What ... ?" Jessica Santana, a 20-year-old municipal worker, uttered to a friend Friday as they walked through Patriarca plaza, eyes fixed high above.

The 31 iron and fiberglass statues bolted atop several buildings are part of the first South American exhibit for British artist Antony Gormley, who has won many awards, among them the prestigious Turner Prize.

The sculptures, based on Gormley's own body, are burnt auburn in color, some with arms slightly bent, others ramrod straight. They appear to stare into the horizon, gazing at the endless sprawl of tall buildings in this city of 20 million people.

The exhibit, "Still Being," officially opens Saturday, runs through July 15 and will also appear in Rio de Janeiro and Brasilia. It includes other works shown in Sao Paulo's Banco do Brasil Cultural Center.

Gormley has spent four decades exploring the theme of the human body and how it relates to larger physical spaces around it, challenging spectators with showings that go well beyond a closed gallery.

"The police were here a few days ago because they received calls that a man was going to jump from a building," said Carol Menezes, a receptionist at a Banco do Brasil building where one of the statues sits on a roof 25 stories above the sidewalk. "It's interesting, creative. I was surprised when I first saw it. I guess it's art, so many strange things are so why not this?"

Gormley's 31 sculptures are part of his "Event Horizon" project, which was shown in London in 2007 and last year in New York, where police responded to at least 10 callers reporting potential suicide jumpers in the first few weeks it was shown.

The New York exhibit provoked a strong reaction. After witnessing people leaping from the World Trade Center towers in the 9/11 attacks, a human form perched atop buildings in that city is particularly unnerving.

"I never wanted to freak anyone out," Gormley told the New York Times in a March 19, 2010, article. "If people think of death and suicide, it's a sad reflection on evolution."

The reaction so far to the Sao Paulo exhibit proves it's not only New York that is reflecting sadly — even in Brazil, whose citizens are routinely ranked among the happiest and most optimistic in international polling. The Folha de S. Paulo newspaper labeled the figures as "suicide statues" in a headline.

"It scared me, I didn't know what to think. My heart raced, I thought it was a guy getting ready to jump," said Santana, a few minutes after realizing the figures were not human.

She then stopped talking, returned her gaze to the skyline, hands on hips, and stood amid the midday buzz of the plaza, as still as the statues high above.