Eleven government doctors in India’s western state of Rajasthan have been suspended on suspicion of carrying out sex determination tests and aborting female fetuses, officials said on Thursday.

Despite laws banning such tests, used to abort unborn girls, female infanticide is common in several regions of India where families view boys as being a better asset than girls.

Social activists say local authorities have been slow to implement legislation that has been in force since 1996. There has been only one conviction from 387 cases lodged under the Pre-natal Diagnostic Techniques Act (PNDT).

“We, in the last over 45 days, have suspended 11 government doctors and are taking action against 30 private doctors on charges of violating the PNDT act and practicing female feticide,” a senior official from Rajasthan’s health ministry told Reuters.

The move comes after an undercover television report into abortions of unborn girls, which exposed doctors carrying out sex determination tests and convincing mothers to terminate pregnancies if the fetus was female.

A joint study carried out by researchers in India and Canada recently suggested that a half-million unborn females may be aborted in India every year.

Officials say states like Rajasthan, Punjab, Haryana, Gujurat, and Himachal Pradesh, and cities like Chandigarh have heavily skewed sex ratios. Even middle class parts of the capital, New Delhi, have far more boys than girls.

In Rajasthan, there are 922 females to every 1,000 males, but officials say in states like Punjab and Haryana, the sex ratio could be as low as 500 or 600 females to 1,000 males.

In March a doctor and his assistant were jailed for two years and fined 5,000 rupees ($110) for carrying out sex determination tests in the northern state of Haryana.