A seventh-grade student released pepper spray in a Northeast Washington school yesterday, sending 20 students and a teacher's aide to area hospitals for evaluation and treatment, authorities said.

The 14-year-old girl sprayed the chemical irritant about 11:30 a.m. in a first-floor hallway of Browne Junior High School, in the 800 block of 26th Street NE, officials said. Police said that she did not appear to be targeting any students or teachers, and school officials said that she probably did not intend to harm anyone.

Several dozen students complained of feeling sick and said their eyes were burning. Police and ambulance crews were called to the school, and paramedics treated some youths with oxygen before taking them to hospitals.

The Department of Fire and Emergency Medical Services said that 20 students and an adult aide were transported and that no one was seriously hurt.

The school was not evacuated, though students were moved out of classrooms and into the auditorium during the episode. Some classes later were shifted to nearby Spingarn Senior High School. By 2 p.m., those students had returned to Browne, officials said.

School officials said the girl intentionally set off the spray as classes were changing and some students were heading to lunch.

"She meant to spray it," said Gloria Grantham, an assistant school superintendent. "I don't think it was malicious. . . . It was just a matter of a seventh-grader using bad judgment."

The girl, whose name was not released because of her age, was charged as a juvenile with illegally possessing a self-defense spray. It is illegal for anyone younger than 18 to have such sprays, police said.

Authorities said the girl took the canister from her parents without their knowledge. She is scheduled to appear today in D.C. Superior Court.

Police and other law enforcement officials sometimes use pepper spray to subdue unruly people and crowds. It causes eye irritation and is designed to impair people's sight for several moments without any lasting damage. It also can irritate the skin, throat and lungs.

Yesterday's incident was at least the second release of pepper spray at a D.C. public school in two years.

In January 2003, a student released pepper spray at Ronald H. Brown Middle School in Northeast, sending 29 students and one security guard to the hospital with breathing problems and other symptoms. None was seriously ill.