To the protesters, it's Guantanamo on the Hudson. Police prefer the acronym PASS, though nobody gets one.

Either way, the dilapidated, hulking pier on the Hudson River in Manhattan has become a landmark of sorts in the clash between activists and authorities at the Republican National Convention.

Some protesters have complained bitterly about conditions at the temporary holding area set up at Pier 57 for processing convention-related arrests. One former detainee, Andrew Lynn, claimed he was held there for hours on end in "Guantanamo-style pens" — a reference to the U.S. military facility in Guantanamo Bay, Cuba.

Police insist their Post Arrest Screening Site (search) allows them to process mass arrests safely and promptly and avoid overwhelming neighborhood stationhouses.

Commissioner Raymond Kelly (search) has dismissed complaints about conditions, including questions about asbestos. Testing Monday night found no problems with air quality, he said.

"There have been some exaggerated claims and outright falsehoods," Kelly said.

NYPD officials declined a second request to allow an Associated Press reporter to tour the site Wednesday, saying officers were too busy processing the nearly 1,000 people arrested the day before.

Among them was an AP photo messenger who was taken in along with a group of protesters when police broke up a demonstration that she and a colleague were covering.

Jeanette Warner was there for several hours. She said conditions were far from inhumane, although the facility was dirty and the experience exhausting.

"It was like a warehouse. It was the best they could do," Warner said. "You didn't want to sit on the floor, that's for sure."

Detainee JoAnn Wypijewski, a 48-year-old freelance magazine writer, said officers manning the makeshift lockup were polite.

"You get the feeling that they're being held prisoner too," Wypijewski said. "It's not a great working environment in there."

Sitting less than 20 blocks south of Madison Square Garden and extending hundreds of feet into the Hudson, Pier 57 once was a terminal for cruise ships. In the 1950s, the city erected a three-story, concrete garage for city buses.

The NYPD recently took over the garage, which closed last year. The department says it cleaned up a section of the interior and built a series of chain-link holding pens in preparation for the convention.

Officers search and interview the detainees at the pier before busing them to a booking facility in lower Manhattan, where they are either given tickets and released or held for a court appearance. Police say protesters typically wait about 90 minutes before being transferred.

While they wait, they are offered milk and sandwiches — bologna, cheese or peanut butter — and each detainee is handed a small paper cup which they can fill with water from coolers inside the pens, Warner said. They are allowed to use portable restrooms alongside the pens.

As they waited Tuesday night, some chanted "This is what a police state looks like," and one woman was put back in handcuffs after she rattled the chain-link fence and jumped against it. For the most part, however, detainees got along well with the officers posted there, Warner said.

Many of those arrested are veterans of other demonstrations where "few got arrested and most got away after breaking the law," Kelly said. "Here, they are being surprised by the fact that the opposite holds true: Most of the lawbreakers will be apprehended and only the law-abiding will get away."

At a news conference Tuesday outside the holding facility, Lynn, civil rights lawyer Norman Siegel and transportation union officials raised concerns about possible asbestos contamination and complained that people were being held too long.

Jay Bermudez, a former shop steward at the bus depot, said, "We've always had a problem here with safety issues." He claimed a fire in 1994 released asbestos into the air.

Lynn, who described himself as an independent videographer, said he was arrested last week at a bike ride protest and held at Pier 57 for 18 hours.

The protesters, Lynn added, were held 40 to a pen and forced to sleep on floors covered with motor oil. Police say they could sit on benches.

Conditions were "absolutely disgusting," Lynn said.