BOULDER, Colo. (AP) -- Police are investigating after someone dropped off several containers filled with potential explosives at a hazardous materials collection site in east Boulder.

Sgt. Pat Wyton says police were called to the Hazardous Materials Management Facility at about 2 p.m. Saturday and found several 1970s-era containers filled with dangerous explosive materials that were likely meant for use during mine blasting.

The center was evacuated while a Boulder hazmat team loaded the containers into a trailer and transported them to another location where they will be stored until they can be properly disposed of.

The Daily Camera reports explosives are among the types of waste not accepted by the facility.

Wyton says it's not clear who brought the containers to the site.