BEIJING, Sept. 1 (Xinhua) -- China's Education Ministry on Thursday reaffirmed its stance that public schools are not allowed to exact extra fees from the children of migrant workers.

Public schools offering compulsory education, which includes elementary and junior high schools, are not allowed to charge the children of migrant workers any tuition, miscellaneous fees or extra fees levied only upon migrants' children.

Nevertheless, there are schools charging migrant children extra fees as "contributions" to schools. Since 2008, China has put such "contributions" under close scrutiny, making it a focal point in its efforts to rein in tuition irregularities.

According to official statistics, 11.67 million children of migrant workers from the country's rural areas are currently receiving compulsory education in cities, an increase of 12.7 percent year-on-year. About 79.2 percent of them attend public schools.

China's hukou system, or residence registry, binds social entitlements, including education and medical care, strictly to areas where they are registered.

Additionally, the ministry also posted a notice on its official website ordering all schools to ensure one-hour of physical exercise for students each day.

Starting in 2007, a three-year objective was instituted to have students in 85 percent of schools exercise for at least one hour a day.

However, according to the notice, some schools are still spending the exercise hour on academics, following a lopsided pursuit to have students perform better on the exams which parents use to evaluate schools.

A nationwide survey on students' health being carried out since 1985 shows that the health of young students has been deteriorating over the past three decades, the notice said.

Thursday, Sept. 1, marked the beginning of the fall semester for China's elementary and secondary schools.