Health officials are studying the feasibility of putting inbound travelers in facilities near Hong Kong International Airport as "tens of thousands" are expected to arrive in the city in the next two weeks.

Starting on Thursday, travelers arriving in Hong Kong from any foreign country will have to undergo a mandatory 14-day quarantine - mostly at home.

The new quarantine arrangements, valid for three months, were officially in place after the government gazetted on Wednesday night Compulsory Quarantine of Persons Arriving at Hong Kong from Foreign Places Regulation.

Secretary for Food and Health Sophia Chan Siu-chee said the AsiaWorld Expo and North Lantau Hospital were being considered additional processing centers for arrivals stranded at the airport.

Incoming travelers need to submit a health declaration form; they could then be randomly selected for a coronavirus test which entails having their deep throat saliva specimens collected by the authorities. But this process takes quite a long time, explained Chan.

She did not rule out the possibility that sampling tests could be extended to cover all incoming travelers.

Each inbound traveler is required to wear a smart wristband and to download an app that monitors their movements during two weeks of home quarantines.

Chief Information Officer Lam Wai-kiu said the wristband could inform the authorities if its wearer leaves a designated quarantine location.

Lam said the device, developed by a local startup and a local university, only detects a change in the location on the basis of strength or weakness of signals like Wi-Fi, Bluetooth and GPS.

The app will send out an alert and inform both the Department of Health and police when necessary.

The government now has more than 20,000 wristbands in stock, with enough backup supply to handle a surging number of arrivals, said Lam.

Contravening the quarantine rules is a criminal offence punishable by a maximum fine of HK$25,000 (US$3,220) and a maximum six-month jail term.

The newly gazetted regulation is described as a "resolute and rigorous measure" to combat the COVID-19 pandemic.

Exempted from this order are airline and goods vessel crew members, on-duty government officials, on-duty directors of Hong Kong Monetary Authority, the Securities and Futures Commission and the Insurance Authority and essential construction workers tasked to work in foreign places. Experts engaged in research or who provide advice in combating the outbreak to the SAR government are also exempt.

Meanwhile, travelers arriving from the mainland are still subject to the same quarantine rules which took effect on Feb 8.