BANGKOK -- Thailand is preparing to ban smoking in air-conditioned restaurants throughout the country by September, the Health Ministry said Sunday.

"The Health Ministry is preparing to announce a new act to force air-conditioned restaurants to be 100 percent smoke-free zones," it said in a statement.

"The ministry expects the act to be in force by September," it added.

At present, the law requires that 75 percent of a restaurant's area be designated as non-smoking.

But current legislation aimed at protecting the health of non-smokers in public areas still faces enforcement problems and a total ban would be easier to enforce, Health Minister Sudarat Keyuraphan said.

"Authorities should be encouraged to use these laws more seriously, and motivate people to respect non-smokers rights," she said, adding that she would discuss with the Finance Ministry a proposal to provide rewards for people reporting law-breakers.

Smokers generally are facing tougher times in Thailand.

Weekend reports the Health Ministry is likely to introduce a series of 12 warning labels featuring graphic pictures of organs damaged by smoking along with harsh text warnings, to be pasted on cigarette packets within a year.

Thailand would be the third country in the world to use such a campaign, following Canada and Brazil, the reports said.

Meanwhile, health authorities said last month that the addictive habit would be banned in Thai temples, as lung cancer and other smoking-related diseases are the leading cause of death among Buddhist monks.

And in January, aspiring beauty queens were told they faced disqualification from Thailand's Miss Universe pageant if they were caught sneaking a cigarette.