SALINA, Kan. -

Salina authorities are investigating after another threatening note was found in a school.

The latest incident was at Salina Central High School, 650 E. Crawford St., around 11: 30 a.m. Monday. Police said a note left in the school office indicated there was a bomb in the school.

School administrators and resource officers searched the school and found nothing suspicious, police said. There were no changes to students' schedules.

In a statement on USD's 305 website said standard procedures were followed.

"Standard operating procedures were followed: investigate, contact law enforcement and search the building," the district said. "As always, at USD 305 the safety and security of students and staff is our number one priority."

Some parents wanted to know why the school district didn't notify them until the following day.

"That's your child, that's your treasure that you raised," parent Rebecca Norlin said. "You see all this stuff going on in the nation everyday. You worry, could that be my child."

The district said every situation is different and they take the school's safety very seriously.

"Parents send their kids to our schools, they entrust their kids will be safe with us," superintendent Bill Hall said. "We take that trust very, very seriously. It's a tremendous responsibility. So we always make decisions based on what's safe for kids."

Officers do not have a suspect in custody investigators are looking into whether or not this incident is related to another threatening note that was found two weeks ago. They also found a cell phone that had been shot with a gun two weeks ago as well.