Updated

A 15-year-old student has been charged with detonating an acid bomb at his high school as students gathered Tuesday morning, Broward County authorities said.

No one was seriously injured, but nine Marjory Stoneman Douglas High School students were treated at the scene for skin irritations, sheriff officials said. Witnesses and a surveillance video led detectives to Alexander Irvine, of Parkland.

He was transported to a juvenile center in Fort Lauderdale on charges of discharging a destructive device. It was not known if he had an attorney.

"The student did tell police he was very remorseful and he didn't intend to harm anyone," Sheriff's Office spokesman Mike Jachles told the South Florida Sun-Sentinel.

The school was locked down for 1 1/2 hours after the bomb went off shortly before 8 a.m. A bomb squad searched the campus but no other devices were found.

Irvine has been suspended and may face expulsion, according to a letter Principal Ann Andersen-Kowalski sent home with students.