China's education ministry has ordered a study of the quality of school athletic tracks after parents in several places complained that their children's health was threatened by a strange odor emitted from the tracks.

A People's Daily report on Friday quoted ministry official Liao Wenke as saying that use of suspect tracks must be suspended pending further assessment.

Liao cited a series of problems including use of substandard materials due to low bidding prices, poor supervision and possible corruption.

Reports of students getting nosebleeds, feeling dizziness and developing rashes after new tracks were laid emerged recently in Jiangsu, Shanghai and Shenzhen, leading parents and teachers to question how facilities to improve the health of users turned out to be health hazards.

Students at a school in Jiangsu even had to wear masks in class.

Most of China's new schools and kindergartens use rubber running tracks.