More than 20 students were arrested Thursday night in connection with a prank at a Mississippi high school.

WLOX in Biloxi reports that the 21 students from Picayune Memorial High School arrested by the Pearl River County Sheriff’s Office were charged as adults with malicious mischief in an incident that officials have described as a “prank that escalated’ at the school.

The sheriff’s office did not give any specifics about the “prank,” and questions about the incident were referred to the Picayune School District. The school district did not respond when WLOX attempted to contact school officials.

The 21 students arrested were all at least 18 years of age and were taken and booked at the jail until their parents could come to post bond.

Several students under 18 were also taken into custody but were released to their parents in Picayune.