US, California - An 11-year-old girl who died after a fight with a classmate in Long Beach cried, complained of a headache and vomited after the altercation, friends and family said.

Long Beach police said the girl underwent surgery hours after the fight but declined to say what type and have not revealed a cause of death.

"There are still many questions, many questions that cannot be answered," said Long Beach Deputy Police Chief Robert Luna.

Luna said the cause of Joanna Ramos' death remains "undetermined."

Ramos' family as well as some classmates said the two girls had been quarreling over a boy.

"They were fighting over a boy. I told the teacher and, she said she would talk to all the girls on Monday," a friend of the girls' told the Press-Telegram on Sunday.

Police said seven people witnessed the fight. Neither their names nor the name of the other girl involved in the fight has been released.

Joanna's aunt, Celina Cervantes, told KTLA News that her niece vomited and had complained of a headache after the fight and that her mother took her to the hospital. Joanna had no visible wounds. She underwent surgery and was placed in intensive care. "My sister-in-law rushed her to the ER, and two hours later she's gone," Cervantes told KTLA. "It's just sad. Very sad."

Officers were informed about 5:50 p.m. Friday that Joanna was not breathing. Although hospital personnel tried to revive her, she was pronounced dead shortly before 9 p.m., authorities said.

The Los Angeles County coroner's office will determine the cause of the girl's death. No arrests have been made. Anyone with information is asked to call (562) 570-7244.