RICHTON PARK (CBS) — A major brawl broke out Monday afternoon at Rich South High School when students from Rich Central arrived after being evacuated from their school by a bomb threat, authorities said.

High School Bomb Threat, Brawl

The bomb scare at Rich Central in Olympia Fields happened about 1 p.m., and prompted school officials to close the building and bus all students to Rich South in Richton Park, a law enforcement source said.

“It’s been pretty tense,” Rich Township High School District 227 Board president Cheryl Coleman said Monday night.

A student at Rich Central made some sort of bomb threat to a substitute teacher, Coleman said. The teacher alerted administrators, who decided to bus the roughly 1,300 students to Rich South, she said.

As the buses arrived at Rich South, someone inside that school pulled a fire alarm, emptying the building, police and school officials said.

While students from both schools were waiting outside, a large brawl broke out among numerous students, which resulted in injuries to several people and several arrests, the law enforcement source said.

One Rich Central teacher was hit in the head and was taken to an area hospital where he was doing OK Monday night, said Coleman, who spoke with the teacher.

“It’s just basically a very sad situation to happen, when I know that the hearts of the administrators were trying to do the right thing for the safety of the kids,” she said.

“That is our rival school. It’s been that way for years. We can’t even have basketball or football games on Friday night without us fighting,” said Rich Central Student James O’Banner

Richton Park police, as well as officers from Olympia Fields, Frankfort and the Cook County sheriff’s police responded to the melee.

According to a release from the Richton Park Police Department, A total of 10 students were charged with a Class 4 Felony- Mob Action, including a 17 year old, Crystal Gholson of Country Club Hills who was charged as an adult.

Police say surveillance video from Rich South led to juvenile charges for a 14-year-old and a 15-year-old suspected of planting the fake bomb and a bomb threat note.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2013. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)