What started Wednesday as a nonviolent demonstration against a planned U.S. Immigration and Customs Enforcement detention center on Salt Lake City’s west side ended with a brief standoff between nearly two dozen protesters and police in riot gear.

After a Tuesday afternoon protest in front of Gov. Spencer Cox’s mansion drew more than 100 people, hundreds gathered Wednesday outside the massive warehouse itself, located at 6020 W. 300 South near Interstate 80 and the airport.

The protest started peacefully at about 6 p.m. with roughly 100 attendees. In less than an hour, the crowd at least tripled.

“This is not the America that I know and love. It’s wrong. It’s inhumane,” said Bridget Verhaaren, an American Fork resident who’d traveled to Utah’s capital to attend the protest. “Too many people I know are being affected by this tragedy. Aren’t we all immigrants?”

ICE quietly purchased the 833,000 square-foot warehouse from a real estate investment trust for $145.4 million last week. The federal agency later confirmed plans to convert the building into a holding facility.

Protesters on Wednesday chanted and waved signs with captions such as “No SLC ICE Detention Center” and “Stay Salty/Melt ICE.” About two dozen attendees waved American flags and some trucks driving by honked to the crowd’s cheers.

Many referred to the proposed ICE facility as an emerging concentration camp in Utah’s midst and called for it to be blocked from ever opening. Several signs referred to Topaz, a Utah-based internment camp for Japanese residents during World War II.

“It shocks my conscience,” said Steve Klemz, a retired Lutheran pastor from Salt Lake City.

Klemz added that the ICE detention center was set to “profit on the backs of those who are made to suffer.”

As the protest wound to a close near sunset, a group of about 60 participants broke from the main crowd as some of them sought to vandalize the front door of the warehouse, after some had plastered graffiti on a small outbuilding. A brief altercation broke out between a handful of protesters and two agents who emerged from the warehouse.

By 7:45 p.m., a contingent of Salt Lake City police officers with riot helmets and half-dozen patrol cars deployed in front of the warehouse. Most of the remaining crowd dispersed at their urging.

About 20 protesters persisted past 8:30 p.m., taunting officers as police regrouped alongside the building. One protester was taken into custody around 9 p.m. at the entrance to the building’s parking lot.