Photo of teen with gun prompts brief lockdown at Eastside Catholic School

SAMMAMISH, Wash. -- Eastside Catholic School was placed on a brief lockdown Friday afternoon after police received suspicious reports regarding student safety, authorities said.

The King County Sheriff's Office said a photo of an 18-year-old student holding a gun was discovered on social media.

The student had previously been expelled from Eastside Catholic.

When other students reported that he was heading to school on Friday afternoon, police responded.

The school was evacuated, and police searched the grounds for the student at about 3:30 p.m.

The student was found a short time later in Issaquah, where he was detained.

No weapons were found on him, at the time of the arrest and no one was hurt during the lockdown.

It's unclear when the photo was reported to authorities.