The study conducted by the Aga Khan University shows that 16 per cent of girls have tried smoking by the age of 15, while over six per cent smoked at least once a month by that age.

Interestingly, the users were found to be aware of the hazards of smoking. The university, which published its study in the International Journal of Tuberculosis and Lung Disease, interviewed 644 Karachi girls with an average age of 15.

The sample was drawn from both government and private schools in the southern port city. A self-administered questionnaire was used to collect data.

While most girls admitted to smoking to keep a check on their weight, the findings endorsed other studies which suggest that sex differences in tobacco use are disappearing and that tobacco companies are aggressively targeting women in developing countries.

The percentage of Pakistani teen girl smokers is higher than that reported in some Indian cities as well as neighbouring countries like Indonesia, Myanmar, Nepal and Sri Lanka.

"It is distressing how often studies of girls' smoking rates in countries previously protected by cultural and religious factors are finding results well on the way to catching up males of comparable age," said a report in the Tobacco Control Journal, which cited the study.

"Just a decade or two ago it was still assumed by most people in Pakistan that it was not even worth trying to measure schoolgirls' smoking as it was negligible. However, as often illustrated in this Journal, international tobacco companies, led by British American Tobacco, have let loose the might of their practically limitless promotional budgets in Pakistan, seeking to hook their next generation of regular smokers -- the youth market -- knowing that they could look forward to recruiting increasing numbers of girls," the report said.

"Girls increasingly have joined the general youth market being exploited by multinational and local companies, at least in the cities, where they have been exposed to promotions in the streets, discos and on televised pop music."