NANCHANG -- Six middle school students were trampled to death and 39 others were injured in a stampede at a school in east China's Jiangxi Province on Saturday evening, local government sources confirmed on Sunday.

The stampede happened at around 8:30 p.m. when hundreds of first-grade students at Tutang Middle School in Duchang County swarmed out of their evening classes and onto the stairway.

Six students, five male and one female aged between 12 and 13, died on their way to hospital. Eleven students are seriously injured and receiving treatment in the Jiujiang No. 1 People's Hospital, according to the county government.

A first-grade student who witnessed the accident said he saw someone squatting down to tie shoelaces on the staircase between the first and second floors of the three-storey building. The events that followed are unclear but another student, Jiang Minxu, from a Grade two class, said that more than 100 students fell on top of each other as their momentum carried them forward.

"Teachers quickly climbed from the first floor to the second floor using the drainpipes on the outside of the building. They helped the students up one by one," said Jiang.

When the stampede occurred, teachers of the school were correcting students' mid-term exam papers in an office on the first floor of the building. It appears many students were unsupervised in the school, which has 50 teachers for 1,600 students. There are six grade-one classrooms in the building, each packed with about 100 students.

The local government of Jiujiang City appear to be holding the school responsible for the incident. The school principal has been detained by the local authorities and the Jiujiang government held a school safety meeting on Sunday for primary and middle school principals in the area and conducted safety inspections.

Each family of the dead students has been given 20,000 yuan (2,500 U.S. dollars) in compensation and local authorities are trying to establish the exact cause of the accident.

The incident raises further concerns on the safety management of Chinese primary and middle schools.

Eight children were killed in a similar stampede that happened in October 2005 in a primary school in southwest China's Sichuan Province, when the students were heading home after evening classes.

Also in October 2005, a boy was killed and 64 others pupils injured in a stampede in a primary school in northwest China's Xinjiang Uygur Autonomous Region, when part of the stairway collapsed.