A fire broke out just before dawn Friday in a rear building at Friendship Capitol High School in north Baton Rouge, torching three classrooms and causing water and smoke damage to 11 more, said Mark Miles, a spokesman for the Baton Rouge Fire Department.

The fire, which was called in at 6:18 a.m., started in Building L of the charter school well before classes started. No one was hurt. Firefighters arrived in five minutes, and the fire was under control by 6:53 a.m., Miles said.

“Once firefighters made their way to the second floor and opened the door of one of the classrooms, they found fire visible and began their attack on the fire,” Miles said.

Students were directed from arriving buses to the gym, where they stayed until classes resumed two hours later in Building M, said school spokesman Justin Blanchard. He said about 320 students came to school Friday, but many were checked out by their parents after the news of the fire broke.

The fire, which caused a still-to-be-determined amount of damage, could prompt the use of another building on the sprawling campus at 1000 N. 23rd St., but school will not stop.

“We absolutely will continue to have school,” Blanchard said.

Miles did not offer a possible cause for the fire and said the blaze is still under investigation, but foul play is not suspected.

Blanchard said an electrical problem is the most likely early candidate.

Capitol High School was built in the early 1960s and in fall 2014 was rechristened Friendship Capitol High. It is run by Washington, D.C.-based Friendship Schools, a charter school network. Charter schools are public schools run by private organizations.

The facility, however, is still owned by the East Baton Rouge Parish school system. The school system ran the neighborhood high school until 2008, when it was taken over by the state-run Recovery School District after years of low academic performance. Parish school officials came out Friday morning to assess the damage.

In a statement, RSD Superintendent Patrick Dobard promised to work with the school system for “the expeditious repair of the facility.”

RSD and parish school officials, after years of conflict, in January worked out a repair process for RSD facilities in Baton Rouge.

Friendship officials already have reported facility problems in the old high school. Blanchard said Building L, where Friday’s fire occurred, was used heavily because of roof leaks in neighboring Building K.

The extent of damage to instructional materials, technology and furniture was still being determined. Firefighters used tarps to try to protect computers from water damage as the fire was being extinguished, Miles said.

By early next week, Blanchard said, he expects to have a better idea of what can be reused and what will have to be replaced.