The World Health Organization (WHO) issued a report on Tuesday on electronic cigarettes that called for regulation of the devices and their contents, bans on indoor use, advertising and sales to minors.

The report will be debated by member states in October at a meeting in Moscow. The WHO has expressed concern at the concentration of 3 billion dollar market in the hands of multinational tobacco companies.

A decade ago, the health agency declared war on "Big Tobacco," finalizing the WHO Framework Convention on Tobacco Control, the world's first public health treaty that has been approved by 179 states since entering in 2005.

Prior to Tuesday's report, WHO had pointed it would favor applying the same restrictions to all nicotine-containing products including smokeless ones.

The WHO has said that e-cigarettes must be regulated in order to reduce emissions and content of toxicants, and solutions with candy-like and alcohol-drinks flavors must be banned, and vending machines should be removed in almost all the locations.

However, scientists are divided on the benefits and risks of e-cigarettes, which are considered to be less harmful, when compared with conventional cigarettes.

In May, a group of researchers warned WHO not to categorize e-cigarettes as tobacco products, contesting that doing so would endanger a major opportunity to reduce diseases and deaths caused by smoking.

178 countries are parties to the FCTC and are obliged to implement its measures, with the U.S. being the one non-signatory.

Major tobacco companies such as Altria Group (MO.N), Imperial Tobacco (IMT.L), British American Tobacco (BATS.L) and Philip Morris International (PM.N) are introducing their own e-cigarette brands as sales of conventional cigarettes drop in Western markets.

U.S. sales of e-cigarettes would overtake conventional ones by 2020, according to a Wells Fargo analyst report in July.