Two students were shot with one bullet at a Los Angeles high school when a student dropped a backpack containing a gun and it went off.

An AP report says that a 15-year-old girl and a 15-year-old boy were seriously injured. Both teens were hit with the same bullet, the report says.

John Deasy, deputy superintendent of the Los Angeles Unified School District, said there was no indication the student had touched the gun before it discharged. "He literally dropped his knapsack on the desk and it went off," Deasy said.

The shooting occurred in a classroom at Gardena High School, where Principal Rudy Mendoza said students were on a break at the time. The campus was locked down after the incident.

School district spokeswoman Gayle Pollard-Terry said that arriving students are checked with security wands on a random basis at Gardena High, so it's unclear how the student got in with the gun in the backpack. No district school is equipped with walkthrough metal detectors.