LA VISTA, Neb. (AP) — Authorities have continued to search this weekend for an autistic 11-year-old boy who has been missing since he walked out of his elementary school last Monday in La Vista, which lies just southwest of Omaha.

La Vista Police focused their search for Ryan Larsen Saturday on Walnut Creek Recreation Area, which is a large park with a lake, wooded areas and miles of trails.

Police used K-9 teams and a State Patrol helicopter assisted from the air.

In addition to the local search effort, police said details about Larsen’s disappearance have also been posted on the National Center for Missing and Exploited Children’s website.