Ambulances at Frederick Memorial Hospital were being rerouted for a couple hours after a suspicious package was brought there Tuesday, police said.

Two men opened the package at a residence on Military Road and went to the emergency room after with the package after complaining of “various respiratory problems and burns”, police said. 

Officials said the packaged contained a "common household chemical", but could not say what at this time. 

At one point the hospital stopped taking any more ambulances or new patients. The hospital has since reopened.

Frederick fire officials said they are going to run a "secondary confirmation," on the substance.