LONDON - More than 94 percent of the world's people are not protected by laws against smoking, leaving them exposed to the biggest cause of preventable death, the World Health Organization said on Wednesday.

In a Global Tobacco Epidemic report the WHO said smoke-free policies were crucial to reducing the harm caused by second-hand smoke, which it said kills around 600,000 people prematurely each year and causes crippling, disfiguring illness and economic losses reaching tens of billions of dollars.

The report found some progress had been made, with 2.3 percent of the world's population, or around 154 million people, newly covered by smoke-free laws in 2008. But it warned of many more early deaths if governments did not act quickly.

"The fact that more than 94 percent of people remain unprotected by comprehensive smoke-free laws shows that much more work needs to be done," said the WHO's expert on non-communicable diseases, Ala Alwan.

Scientific evidence has unequivocally established that exposure to tobacco smoke causes death, disease and disability. Over the past four decades, smoking rates have fallen in rich places such as the United States, Japan and western Europe, but they are rising in much of the developing world.

The WHO said seven countries - Colombia, Djibouti, Guatemala, Mauritius, Panama, Turkey and Zambia - brought in comprehensive smoke-free laws in 2008, bringing the total to 17.

Tobacco is the leading preventable cause of death in the world, killing more than 5 million people a year. A report by the World Lung Foundation in August said smoking could kill a billion people this century if trends hold.

"Unless urgent action is taken to control the tobacco epidemic, the annual death toll could rise to 8 million by 2030," the WHO report said.

"More than 80 percent of those premature deaths would occur in low- and middle-income countries - in other words, precisely where it is hardest to deflect and bear such tremendous losses."

The WHO report found that tobacco control remains severely underfunded, with 173 times as many dollars collected worldwide in tobacco taxes each year than are spent trying to get people to stop smoking.

Progress on implementing bans on tobacco advertising had stalled, it said, and progress on increasing tobacco tax had come to a halt, with nearly 95 percent of people living in nations where tax is less than 75 percent of the retail price.

The WHO urged governments to implement its framework convention on tobacco control, which 170 nations have signed.

The convention urges countries to adopt measures to prevent smoking and protect people from tobacco smoke. It also advocates offering people help to quit, enforcing bans on tobacco advertising and raising tobacco taxes.

At the moment, less than 10 percent of the world's population is covered by any one of these measures, the WHO said.