ARNOLD, Missouri-  KMOV reports an Arnold police officer sustained life-threatening injuries after being shot by an unknown suspect Tuesday.

Both the officer and the suspect are in the hospital, and the condition of the suspect is unknown. The incident apprently happened while the suspect was being transported and he may have has his own weapon.

The circumstances of the shooting are not clear at this time, but Arnold police have cordoned off an area of the department’s parking lot behind the building, the report says.

Arnold is the largest city in Jefferson County and is in proximity to St. Louis. The population was 20,808 at the 2010 census according to Wikipedia

News 4 is on the scene and will continue to update this story as it develops.