All schools in the city of Shoreline, a suburb north of Seattle, were in lockdown for several hours Wednesday morning "due to police activity," according to the Shoreline Public Schools website. The lockdown ended in late morning, but classes were canceled for the day.
Local news outlets reported that a gunman was reportedly seen on the grounds of an elementary school, wearing a black hoodie and carrying a rifle.
No gunman has been located but authorities are continuing their search, officials said.
All of the students were reportedly safe.
"Deputies launched a search for the suspect using K-9 police dogs, canvassing the entire area surrounding the Meridian Park school," according to the KOMO News website. "The manhunt has created a backup on North 175th Street from Interstate 5 westbound, and motorists were warned to avoid the area."
Calls to the Police Department were not immediately returned.