Chaska police said Wednesday they've arrested a juvenile male in connection with threats that closed the high school Tuesday.

Police said the juvenile, who is in custody, acted alone.

Chaska High School canceled classes for its 1,250 students after it was locked down Tuesday morning once the school received the threat. School officials declined to reveal the details of the threats, saying they fear "copycat things."

A police sweep of the high school and parking lot came up empty, district spokesman Brett Johnson said.