Updated 9:00 p.m. Dec. 16, 2014

A masked thief wounded a clerk with a shotgun blast during a robbery at an El Cajon motel Tuesday afternoon before fleeing into the surrounding neighborhood, prompting an intensive police search and a lockdown at nearby Grossmont High School.

The armed bandit confronted the employee at the Quality Inn, 1250 El Cajon Blvd., and demanded cash about 1:30 p.m., according to police.

The worker told the robber not to shoot and tried to escape into a back office, at which point the assailant fired one round, then left the business and ran off to the west, Lt. Walt Miller said.

Medics took the victim to Sharp Memorial Hospital in San Diego for treatment of an apparently non-life-threatening wound to his lower back. He was expected to be released from the trauma center later in the day.

Administrators at the nearby high school directed teachers to kept students secured inside their classrooms as a precaution while officers combed the area for the assailant.

About 3 p.m., school officials began releasing the teens one classroom at a time, said Catherine Martin, spokeswoman for Grossmont Union High School District. Parents were directed to pick up their children at the Murray Drive campus.

The lockdown was lifted just before 3:30 p.m., according to police.

The robber remained at large as of early evening. He was described as a roughly 6-foot-2-inch white man wearing a gray hooded sweat shirt. During the heist, he had some sort of mask covering his face, the lieutenant said.

— City News Servce