(Meriden, KS) -- Jefferson County officials are on the lookout for someone that got into Jefferson West Middle School Monday morning.

A janitor called authorities when she said she saw a man with a backpack in the school well before school started before 6am Monday.

The person and backpack raised concerns so the sheriff's office says they delayed school for an hour while they used a bomb dog to sweep the school, then asked teachers to check their classrooms.

No one found anything and school resumed Monday morning at about 8:30.

Parents were sent this note from school officials:
"Early this morning a custodian discovered someone in the Middle School who should not have been there. The police were called and the building was searched. The students and staff remained outside until the all clear was given at 8:15am. Everyone is safe and school has resumed as usual."

This comes after another odd incident on Friday - the same janitor told officials she was in a cleaning closet that morning, also before school, when someone barricaded her inside. No word if that was the same man the janitor saw Monday.

The Jefferson County Sheriff's Office asks anyone that might have seen a man in or around Jefferson West Middle School Monday morning to call the sheriff's office at 785-863-2765. The unknown person was seen wearing dark clothes and a dark backpack.