Seven teachers and three safety officers were injured when two fights broke out at Cheltenham High School on Wednesday, the school district acknowledged Thursday morning.

The most seriously injured staffer was a long-term substitute teacher who tried to break up a fight involving four female students in the school Wednesday morning and was taken to a hospital in an ambulance.

There was a second "physical altercation" Wednesday afternoon, Susan O'Grady, a district spokeswoman, said in an email. Details of that incident were not immediately avalable. A breakdown of when the other staff members were injured, also was not immediately available.

The morning fight started between two girls in a hallway as students were leaving homeroom for first period. Two of the girls' friends also started fighting, attracting a crowd of about 50 to 60 students. Police were called, and the teacher was taken away in an ambulance.

Ray McFall, principal of the 1,500-student school in Montgomery County, sent a letter to parents Wedneday, saying students got into a fight at 7:30 a.m., but he did not mention a teacher being hurt. He said staff members intervened, police were called, and the students were quickly removed from the building.

Superintendent Wagner Marseille sent another letter to parents saying students who fight would meet with appropriate consequences, including possible expulsion. He also said four administrators and four additional safety officers would be assigned to the high school for the remainder of the week.

The four females involved in the morning fight — three juveniles and an adult — were taken into custody and charged.

Court records show Amber Lewis, 18, was charged with aggravated assault, simple assault, harassment and recklessly endangering another person. She was being held at the Montgomery County Prison after failing to post $10,000 bail and faces a May 12 preliminary hearing, according to the records.

After the fight, first period was extended and teachers were told to lock their doors and keep students in classrooms, according to a person who was in the building but did not want to be identified.

The source said the injured substitute teacher was struck on the head by one of the students. She then fell into a locker, hitting her head. She was on the ground crying as she waited for paramedics to arrive. Eventually she was put on a gurney and wheeled out of the building.

Some students photographed the fight.

Cheltenham police have not issued a public statement on the incidents at the school, where students told TV outlets that fights have become daily events.

In his letter, McFall said that additional adults were brought into the building to monitor the hallways and outside areas. Counselors were available for students to talk about the incident.

"The school is safe and calm; classes and our AP testing are both proceeding as normal, and all after-school activities will proceed as regularly scheduled," McFall said.

He said the incident was "a gross violation of our code of conduct," and encouraged parents to speak to children about how to manage stress. He said the district would not tolerate fighting or the photographing of fights.

"Both behaviors are beneath us and reflect poorly on our larger population," he said. "Those students who decide to fight in school intentionally compromise their right to learn in our school. Those who are found to have filmed a fight will meet with swift disciplinary actions."