China's high-pressure, exam-driven education system is responsible for the vast majority of suicides by schoolchildren in the country, state media said Wednesday, citing a study.

Official statistics on youth suicides are hard to obtain, but a health ministry journal said that about 500 primary and middle school students kill themselves every year.

A study of 79 such suicides last year found that almost 93 percent happened following arguments between the pupils and their teachers, or after the students experienced heavy pressure with their studies.

Most killed themselves because "they could not bear the heavy pressure of the test-oriented education system", said the findings, quoted in the state-run China Daily newspaper.

The 2014 Annual Report on China's Education was released Tuesday after a spate of suicides caused concern over the country's high-pressure education system, where progress is based on key tests, including entrance exams for high school and university.

In January last year, a student in Inner Mongolia jumped from the top of a building after learning that his test scores had dropped, the China Daily said.

Earlier this month a 13-year-old boy in Jiangsu province hanged himself after he failed to finish his homework, the newspaper added.

The school day can be as long as 12 hours in China, and students can typically expect between two and four hours of homework on top of that.

Many Chinese parents also take a highly disciplined approach to education, strictly enforcing their children's studies.

The study found that almost two thirds of the suicides came in the second half of the academic year, when exams are taken.

Chu Zhaohui, a senior researcher on basic education at the National Institute of Education Sciences, told the China Daily more communication was needed between students and their parents and teachers.

"Parents and teachers should often talk to the children, get to know their needs and respect their thoughts," Chu said.

"This is a simple thing to do, but really effective."