ZHENGZHOU - A teacher's decision to use corporal punishment might have influenced a school girl to commit suicide in Luoyang, a city in Henan province, according to an initial investigation.

On Saturday, authorities from Luoyang's educational department sent an investigation team to look into the death of a 13-year-old junior high school student who had jumped to her death the day before.

A report by the educational bureau said that a math teacher had punished the girl and several of her classmates for not doing their homework on time by making them do squat thrusts - an exercise in which a person first squats down, then thrusts his legs out horizontal to the ground, then returns to the squatting position and finally stands up. The report called the teacher's commands "corporal punishment in disguised form".

Educational authorities are assiduously pursuing the investigation, said Han Jingquan, deputy chief and spokesman of the city's educational department.

Anyone who is found to bear responsibility for the girl's death will be dealt with sternly, he said.

At the same time, Han rebutted allegations made previously by an unnamed source on an Internet forum.

The post, which linked the girl's suicide directly to the punishments, said she was required to do 800 squat thrusts at a time, and was beaten and insulted by her teacher after she had fallen over due to exhaustion.

According to the post, the girl jumped from the top of a six-story building on Friday afternoon "because she was suffering from too much physical and mental pressure". Her body was discovered by her mother.

"Her parents are so sad that they cannot talk about this anymore," the girl's aunt said on Monday.

The girl's father, Yu Jianwei, was quoted by local media as saying that his daughter showed no signs of being depressed when he spoke to her on the telephone at noon on Friday.

He said she had complained to him and his wife twice in the past about her teacher and about the squat thrusts.

The teacher and the headmaster at Luoyang's Experimental Middle School, which the girl attended, could not be reached for comment on Monday.