Severe overcrowding at an immigration facility in El Paso presents an immediate risk to the health and safety of hundreds of migrants being held there, with some of those detained standing on top of toilets in crowded rooms just to find air to breathe, a federal watchdog said this week.

In a report issued Thursday in which it calls for immediate action, the United States Department of Homeland Security’s Office of Inspector General detailed several striking observations about the conditions at the El Paso Del Norte immigration processing center gathered during unannounced inspections in early May.

Despite federal standards saying that people should generally not be detained for more than 72 hours, some people were held in “standing room only” cells for weeks, the report said. Investigators found that there was limited access to showers and clean clothes, the report said. Some people were “wearing soiled clothing for days or weeks,” the report said.

Investigators found 155 people in a cell that was supposed to hold 35, and 41 people in a cell that was supposed to hold eight. Nine hundred people were being held at the center on one day in May — far exceeding its capacity of 125.