Grand Junction police are trying to find out who left a backpack loaded with improvised explosives near an apartment complex.
Police described the devices as bottles and canisters filled with gunpowder, sealed by duct tape with fuses attached.
An entire building in the Racquet Club apartment complex was evacuated for more than two hours Sunday afternoon after the bomb squad was called to defuse the devices.
A Grand Junction Police Department spokesman would not say whether the items were actually capable of exploding, confirming only that they were homemade.
As of Sunday evening, no arrests had been made. Police would not say if they had any suspects in the case.