Oakland residents sought shelter last night as hundreds of police officers tried to break up a… Oakland residents sought shelter last night as hundreds of police officers tried to break up a peaceful protest that began in Schenley Plaza.

Pitt police Chief Tim Delaney estimated that at least 100 people were arrested after police officers from the University, city and other states tried to disperse a G-20 protest.

Around 10 p.m. yesterday, about 50 demonstrators stood in Schenley Plaza.

Some people in black clothes played a version of duck-duck-goose that they called “anarchist-anarchist-cop.” A man who was speaking into a microphone advocated nonviolence and said that the Sept. 11 attacks were part of a conspiracy.

At 10:05, the University issued an emergency message, the second of the day, along the Emergency Notification Service: “Conditions may be deteriorating in Oakland. Students are advised to remain near their residences.”

The University sent out an alert via text message, phone calls and e-mail at 7:28 p.m. that warned students to exercise good judgment and be careful, as more G-20 disturbances could occur that day.

Earlier in the day, attendees of the People’s March, which ran from Oakland to Downtown, handed out fliers encouraging others to assemble in the plaza.

But the people gathered in Schenley Plaza appeared to be doing little more than playing games or standing around talking.

Police began to surround the park about a half hour into the protest. The police encircled the plazas in lines that were about two or three officers deep.

Police vehicles and school buses delivered more officers to the area.

The police brought in a Long Range Acoustic Device, which sends piercing noises or spoken messages in aimed directions.

By that point, around 200 people had gathered in the plaza and surrounding area.

Some people were heard saying, “Let’s get out of here.” Others started to scream, “This is what a photo-op looks like.”

By 11 p.m., a helicopter was hovering over Forbes Avenue near the William Pitt Union.

Officers declared the gathering an “unlawful assembly” and told people to disperse or risk going to jail.

The problem, Delaney said, was that Schenley Park closes at 11 p.m.

“We could not have what happened last night,” he said, referring to a demonstration-turned-riot Thursday that resulted in damage to at least 10 Oakland businesses.

Police announced nine times that people should disperse from Schenley Plaza and the surrounding area. One time, they played their pre-recording warning message in Spanish.

Crowds began to gather as students watched from the Cathedral lawn.

Many of the people gathered in the plaza exited onto Forbes Avenue, eventually turning up Bellefield Avenue. Police outnumbered them at least 2-to-1.

Police used riot gas near the William Pitt Union panther statue and on Towers patio at different times throughout the night.

At one point, what sounded like rubber bullets being shot from a gun were heard on Forbes.

Officers on bikes began to line up alongside the Union on Forbes Avenue, and police with riot shields lined up and began to walk down the street. Police gave the final order to disperse.

By midnight, most of the officers who had been at Schenley Plaza had moved to other areas. Still, a school bus full of officers in riot gear unloaded outside of the Hillman Library on Forbes Avenue.

Meanwhile, a K-9 unit, Humvees and a police line moved down Fifth Avenue towards Downtown.

Central Oakland was virtually locked down. Officers directed pedestrians away from campus.

Just before 1 a.m., police were questioning seven people, who had plastic zip ties — the police equivalent of handcuffs during the protests — around their wrists.

Students observing the arrests said they were upset about the show of police force.

Varun Viswanathan, a Pitt sophomore, said he saw a police officer hitting one individual.

“I think they completely use unnecessary force on us,” he said. “They have no right to do that.”

Pitt senior Ken Egler called the police action “one of the crazier things” he’d seen during last night’s protests, especially since he didn’t see many demonstrators in Oakland.

“I really think it’s ridiculous,” Egler said. “We should be allowed to protest. This is needed, and they’re just basically trying to scare us.”

The police left the area by 2 a.m.