An 11-year-old girl died following an after school fight at a Long Beach elementary school, but authorities say they have no immediate plans for arrests.

Police said Saturday night that the girl died at a hospital hours after the fight with another 11-year-old girl outside the school, which sits about 40 kilometers south of Los Angeles in one of the region’s largest cities. Authorities have not released the girl’s name but the Long Beach Press Telegram said she has been identified by friends as Joanna Ramos.

Police are stressing the unusual nature of the tragedy and are urging caution about linking the fight to the girl’s death pending a coroner’s report on the cause of death.

“I think it’s safe to say this is definitely an isolated incident,” said police spokeswoman Nancy Pratt. “I personally don’t hear of 11-year-old fights like this especially girls. I can’t say they never happen but I think everyone was completely caught off-guard by this event.”

Friday’s fight at Willard Elementary didn’t appear to be especially serious or violent, no weapons were used and neither girl was knocked to the ground, police said. Police could not say what prompted the fight but friends had their suspicions.

“They were fighting over a boy,” said Stephanie Guadalupe, a friend of Joanna. “I told the teacher and she said she would talk to all the girls on Monday.”

The Press Telegram reported the fight was pre-planned. Long Beach Unified School District Superintendent Chris Steinhauser told the newspaper there was no indication that adults at the school, attended by about 800 students in kindergarten through fifth grade, was aware of it or notified about it beforehand.

The students involved in the altercation left an after-school program and went to an alley near the school to fight. Some students said bullying had been a problem at the school but Deputy Chief Robert Luna could not confirm if this was an issue in this incident.

Adults later noticed Joanna wasn’t feeling well and drove her to a local emergency room, Luna said.

She was hospitalized and had surgery but died about six hours after the fight at 9 p.m. on Friday.

“There are times when words do not convey the sense of sadness we feel,” Mayor Bob Foster said at a press conference. “This is one of those times.”

Police are investigating and say no arrests are immediately planned. They have interviewed the girl who fought with Ramos. (AP)