China's Ministry of Health on Wednesday reiterated its warning against the use of ultrasonic and chromosomal examinations in illegal fetus gender identification and abortions.

Ultrasonic and chromosomal examinations in fetus gender identification and selective abortions for non-medical reasons were major causes of the unbalanced birth gender ratio, the ministry said in a statement.

Health authorities must continue their crackdown on the illegal use of the examinations and prosecute practitioners, it urged.

Stricter rules should be introduced in gender identification and abortions, including raising the criteria for the licensing of medical institutes and medical practitioners.

Public and professional awareness of laws and regulations should be raised with the coordination of family planning, culture and broadcasting departments, it said.

Health departments should also work closely with public security authorities and family planning departments in dealing with illegal practices, and encourage information from the public.

Self-discipline and self-supervision must be enhanced in medical institutes and healthcare centers, where the ministry would launch inspections soon.

In China, where sons are traditionally preferred and most couples can have only one child, prospective parents have been known to abort a pregnancy if tests showed the fetus was female. As a result, 119 boys are born for every 100 girls, much higher than the global ratio of 103 to 107 boys for 100 girls.

The government has prosecuted 3,000 cases of gender identification and abortions for non-medical reasons over the past two years. The practice was banned with the adoption of the Population and Family Planning Law and Law on Maternal and Infant Health.