Air passengers departing from Hong Kong have said they were unaware of a new rule limiting the number of power banks they could carry to two, with few reminder signs visible at the airport on the first day of its enforcement on Sunday.

Hong Kong International Airport announced on Saturday night that departing passengers were restricted to carrying no more than two power banks.

Citing new regulations from the International Civil Aviation Organization (ICAO), the Airport Authority said the global aviation body had introduced the requirements to address emerging aviation safety risks posed by lithium battery power banks.

On Sunday morning, no specific notices concerning the latest regulation were displayed at check-in areas, and no public announcements were broadcast to alert passengers.

Most of the existing signs only reminded passengers not to place lithium batteries in checked luggage and not to use power banks during flights.

Just one Civil Aviation Department notice about the new rules was evident near the Great Bay Airlines counters in the departure hall.