About 100 people were arrested late Monday near Civic Center Park after rushing a police safety line just after 7 p.m. MDT, according to a city of Denver press release.
Two officers used pepper spray and one used a pepper ball, which is akin to a paint ball and contains the same eye-searing material as pepper spray.
The protesters were arrested for a combination of obstruction of streets or public passageways, interference, or disobedience to a lawful order.
All were sent to the temporary processing facility, a warehouse on the western outskirts of Denver that has holding cells made of chain-link fences.
Protesters call the facility Gitmo on the Platte for the nearby Platte River and compare it to a dog kennel.
But Capt. Frank Gale of the Denver Sheriffs Department said officials were able to process everyone in four hours without incident.
It went very well, very smoothly, Gale said. Everything ran very efficiently as it was planned to do. A large number showed up, and we were able to process them quickly.
About half of the arrestees immediately posted bond and were bused to the nearby Denver County Jail, where they were released.
The other half went to court, where a judge began to hear cases at about 1 a.m. Tuesday morning, Gale said. Some then posted bond and others pleaded guilty.
Those who posted bond were waiting in the processing facility to be released Tuesday morning, while the others were booked into the county jail.
The city press release said about 300 people gathered at the park Monday evening and refused to disperse, rushing the police line at about 7:15 p.m. Many were observed carrying rocks and other items that could be used to threaten public safety, the release said.
Those arrested started arriving at the processing facility at about 11 p.m., according to Gale.
Nine other people were arrested throughout the day Monday, most for disobedience to lawful order and a couple for trespassing.
A spokesman for Denvers Joint Information Center, which is coordinating all police-related information during the convention, could provide no further details about the Monday evening arrests.