The media sure did keep this one under wraps as so not to embarrass Joe Biden while on his Arizona border-LESS trip, but Denver late Tuesday night scrambled to activate an emergency shelter for roughly 100 migrants who arrived in the city overnight, emergency authorities said.

The group arrived on a bus Monday night at a homeless shelter in the city, according to Mikayla Ortega, communications manager for the city’s Office of Emergency Management. The shelter reached capacity Tuesday, Ortega said, prompting the city to activate an emergency shelter at a city-owned recreation center to house the migrants.

The migrants are from Central and South America, including Venezuela. Most range in age from around 20 to 40 and two are children. They arrived at the rec center around 8 p.m. Tuesday.

“At this time, we are working to stand up an emergency shelter and we anticipate it will be in place while we work with non-profit partners to connect people with resources,” the department said.

The department said it would not release the name of the recreational center “due to the security and sensitivity of this evolving situation.”

Little else is known about the migrants or their situation. It’s not immediately clear, for example, if a border state, such as Texas, sent them to Colorado.

The first major influx of migrants had arrived in Denver several weeks ago. The asylum seekers had crossed the border from Mexico to the U.S. and turned themselves into the U.S. Customs and Border Patrol. Those families, who are from Central and South American countries, arrived in Denver following a 12-hour drive from El Paso, Texas.

The arrival of the new migrants on Dec. 6 occurred amid a heightened debate in Washington, D.C. about illegal border crossings.