After police responded to the Green Park Elementary School (Pictured) in Walla Walla Tuesday morning, the alleged threat was believed to be a very serious prank.

Police received an anonymous call about an allegedly armed person who was at the school. The school immediately went into lockdown, and police were called.

After searching and securing the entire area, police now believe it was a prank, but say it will be treated as a full criminal investigation due to the seriously of the threat.

Anyone who many have any information is urged to call (509)-527-1960. All leads can be confidential.