At least two Hong Kong residents have been penalised for vaping in Admiralty as health authorities begin enforcing a new law banning the public use of alternative tobacco products, including e-cigarettes.

“We will issue penalty tickets without warning, and step up publicity in high-traffic areas such as business districts,” Head of Tobacco and Alcohol Control Office Dr Manny Lam Man-chung said, stressing that the new measure would not undermine tourism.

A patrol in a business district in...