MANILA - Just hours after Philippine President Rodrigo Duterte announced he would ban e-cigarette use, police were ordered on Wednesday to begin arresting people caught vaping in public and to confiscate the devices.

The abrupt prohibition, revealed by Duterte late Tuesday, adds to a growing global backlash against a product once promoted as less harmful than smoking.

Duterte called the devices "toxic" and said vaping introduced "chemicals" into the user's body.

He then threatened to arrest anyone vaping publicly in a country that already has some of Asia's toughest anti-smoking rules.

The president, a former smoker, is notorious internationally for his deadly anti-narcotics crackdown, but he has also targeted tobacco with a wide-ranging ban on smoking in public.

Citing "the order of the president", the head of the Philippine police ordered "effective today, all police units nationwide to enforce the ban on use of vapes; ensure that all violators will be arrested," according to a statement.

Duterte's order came days after Philippine health authorities reported the nation's first vaping-related lung injury, which resulted in a 16-year-old girl being hospitalized.

About 24 percent of Filipinos were tobacco users according to a 2015 World Health Organization study, the most recent available.

E-cigarettes do not "burn" but instead heat up a liquid -- tasting of anything from bourbon to bubble gum, and which usually contains nicotine -- that turns into vapor and is inhaled.

The vapor is missing the estimated 7,000 chemicals in tobacco smoke but does contain a number of substances that could potentially be harmful.

However, critics say that apart from being harmful in themselves, the flavors of e-cigarette liquids appeal particularly to children and risk getting them addicted to nicotine.

E-cigarettes have become hugely popular in the past decade but a rash of vaping-linked deaths and illnesses in the United States is feeding caution about the product, already banned in some places.

In September 2019 India became the latest country to ban the import, sale, production and advertising of e-cigarettes, citing in particular concerns about its youth.

The devices are already banned in several places such as Brazil, Singapore, Thailand and the US state of Massachusetts.

Before Duterte's presidency, the Philippines already had a ban on tobacco advertising, as well as a law that requires graphic images of smoking health hazards to be printed on cigarette packaging. -AFP