LOS ANGELES — Two students were shot and wounded, one critically, inside a Los Angeles middle school classroom Thursday morning and police arrested a female student believed to be 12 years old, authorities said.

A 15-year-old boy hit in the head was transported to a trauma center in critical but stable condition, according to fire department spokesman Erik Scott. A 15-year-old girl with a gunshot wound to the wrist was taken to a hospital in fair condition, Scott said.

Three other people, ranging in age from 11 to 30, suffered minor cuts and scrapes.

Police arrested the female student and recovered a gun after the shooting that happened just before 9 a.m. at Salvador B. Castro Middle School, west of the city’s downtown. Preliminary information indicated she was 12, said Steve Zipperman, chief of the Los Angeles Unified School District police force.

Authorities did not immediately identify a possible motive.