KYLE, Texas—Hays County sheriff’s deputies seized homemade explosives at three homes after a high school student told school officials about bomb-making activities by other students.

School district and law enforcement officials said Tuesday they interviewed each of the four Jack C. Hays High School students involved and are confident there was no plot to harm students or the school.

They declined to say why the students had bomb-making materials or what they planned to do with them.

“I think it was really just ignorance on their part,” said Sheriff Allen Bridges. “I don’t think there was any ill intent. I think it was experimenting, or whatever, in an area they shouldn’t have been.”

The four male students, one of whom is 18 and the son of a Hays deputy sheriff, are suspended pending whatever charges may be filed later Tuesday, Principal Shirley Reich said.

The rest of the students are juveniles.

Bridges declined to immediately release the name of the 18-year-old student.

Reich said a student tipped school authorities Monday after one of the students involved brought a bomb-making “cookbook” to school.

She interviewed the students with their parents at the school. 

She said each of the students was forthcoming with information and detailed for police what they would find at the homes.

Classes were not suspended. Investigators and bomb-sniffing dogs searched high school buildings after hours and found no evidence of explosives on campus.

Investigators also searched the homes and found the incendiary devices.

The devices were destroyed by the Austin Police Department bomb squad.

Bridges would not detail what deputies found in the homes because the investigation was still open.