Shooter holds hostages in home after opening fire at US police officer: Report

MOUNT VERNON - An attacker shot a police officer in the back of the head on Thursday evening local time (Dec 15) in Mount Vernon, Washington, and was barricaded with hostages inside a home where he continued to fire shots.

The Seattle Times quoted authorities as saying the police officer - who was critically wounded - was responding to a report of a man shot, but the circumstances that led to the shooting were not clear. 

State patrol said in the shooting that prompted the police response, a person was grazed by a bullet.

The police officer is said to be out of surgery, and in a serious but stable condition. The suspect is currently in custody.