The updated rules, set out in a document seen by Bloomberg News, will come into effect Wednesday. The strengthened protocols for turnaround cargo pilots and cargo crew, the last remaining category of flight staff to not require hotel quarantine, close a loophole that allowed some to shirk stay-at-home orders because there was no monitoring or checking in place.

Hong Kong is grappling with a renewed COVID-19 outbreak that’s spurred record levels of daily infections, prompting authorities to seek to further limit social activities as the hub hews to China’s COVID-zero policy. On Tuesday, the government approved measures that extend gathering limits to private premises for the first time in a bid to prevent residents from socializing, and limit group sizes in public to two people, down from four.

The Transport and Housing Bureau, which issued the directive, said in an emailed response that its evolving changes factor in public health considerations and the operational needs of airlines.

Previously, aircrew flying to 10 so-called Group A countries—including the U.K. and Indonesia—were required to quarantine for 14 days. And when the rest of the world’s countries were gradually shifted into the highest-risk category since late last year, airlines retained an amendment to quarantine crews coming from most nations for a reduced period of seven days. That’s now been wiped away.

Additionally as part of the enhanced aircrew rules, airlines will be required to supply authorities with some form of “visual documentation” regarding staff working abroad as part of strict audit checks, the document shows, without going into detail about what that might be.

Airlines also won’t be able to mix-and-match locally based and overseas aircrew on the same flight, and all aircrew on the same flight can only fly together if they’re quarantining for the same length of time. For cargo crew based in Hong Kong, the electronic bracelets will need to be worn at all times for the first three days upon return to the city, according to the document.

Considering there are very few carriers flying in and out of Hong Kong, the tightened rules will mainly impact Cathay Pacific Airways Ltd., already subject to twin government investigations into the role it played in staff breaches that saw two infected cabin crew flout COVID regulations last December by dining out.

In the immediate aftermath of those aircrew rule breaches, the government expanded the amount of time crew were required to spend in quarantine, prompting Cathay to slash passenger and cargo flights even further.

Cathay Staff Memo

A Cathay spokeswoman said the airline would continue to comply with all government directives, adding “we will do everything we can to maintain vital connections for passengers and cargo into and out of Hong Kong.”

In a memo to staff from the airline’s general manager operations Mark Hoey, and seen by Bloomberg News, Cathay described the latest measures as “some of the most stringent requirements” yet.

In a separate staff message later Tuesday evening, director of flight operations Chris Kempis said wristbands for crews were the best measure to stop all crews being quarantined in hotels.

“The wearing of wristbands strikes a balance between requiring all crew to quarantine in a DQH (designated quarantine hotel), irrespective of the duty, and allowing those under Medical Surveillance to remain at home,” Kempis wrote.

A separate circular sent to airlines on Tuesday quoted a Hong Kong Transport and Housing Bureau representative as saying the government would “appreciate airlines’ efforts in adjusting their aircrew rosters and flight operations promptly in accordance with the revised air crew exemption conditions.”

“For any out-of-home activity of their aircrew members that cannot be verified, or that is deemed to be disallowed under the exemption conditions, local airlines shall report to the government for potential prosecutions,” the circular said, adding that internal disciplinary proceedings against such aircrew may also be taken.