By Stan Bush

NEDERLAND, Colo. (CBS4) – Federal investigators are working with the Boulder County bomb squad to disarm a possible IED that was left at the Nederland Police Department early Tuesday morning.

According to Nederland police, a backpack was left in front of the police department and was brought inside by a detective beginning his shift at approximately 7 a.m. Shortly after, he opened the backpack and found what appeared to be an improvised explosive device.

Two robots were brought in to disarm the contents of the backpack. Multiple pieces were removed from the device, but police could not confirm if there is still a threat. The pieces were sent to the forensics lab in Boulder to determine their origin and threat level.

Police would not confirm if there is a suspect at large or if the situation is being investigated as a domestic terrorist threat.

The incident happened in a shopping complex that is essentially Nederland’s town square. The small mountain town’s grocery store and multiple shops have been evacuated as being considered well inside the possible bomb’s blast radius.

The area typically has hundreds of people coming in and out at any time of the day.

Police did not say if anyone had made previous threats to the department or if there is surveillance video of the bag being dropped off at the department.

Stan Bush is a general assignment reporter at CBS4. His stories can be seen on CBS4 News at 10. Read his bio and follow him on Twitter @StanBushTV.