Secretary for Security Chris Tang said on Saturday that authorities are working to help Hongkongers who have reached out saying they are being held captive in Southeast Asia. He noted that so far 28 residents have sought assistance after apparently falling prey to scams.

Tang told reporters that 14 are now believed to be safe, with 10 already having returned to the SAR.

As for the remaining suspected victims, the minister said 10 are believed to be in Myanmar and four others in Cambodia.

"We are, on one hand, carrying out investigations here in Hong Kong," he said. "At the same time, we are comprehensively liaising with others, including our foreign ministry, the commissioner's office of the foreign ministry, Interpol, and relevant local authorities, to hopefully – through all means – rescue these people.

"Because this involves rescuing people, it's not suitable to disclose too much about the actual operation."

In addition to using a 24-hour hotline and an app created by the Immigration Department, those who need assistance can now reach out to authorities via WhatsApp on 5190 8909.

"We understand that people who are being held captive might not be able to reach out, then they would have to rely on their family members, or they could inform their family members about what they are going to do and their whereabouts when they are leaving," said Tang. "If there is anything suspicious, I believe their family members should call the police for help in the first place."

He added: "These victims, on many occasions, were asked to contact their family members in Hong Kong to send money. I hope family members here could help report the cases to police."

Asked about whether the suspected victims should be helped to return to Hong Kong first without securing a hotel quarantine booking, Tang said rescuing people was the most important thing, and that everything else could be handled separately.

The security chief said authorities would raise public awareness on the issue through social media and giant screens across the city, in addition to offering reminders at the airport for travelers to Southeast Asia to be wary.

Separately, Secretary for Commerce and Economic Development Algernon Yau, who is set to travel to Cambodia next month to meet other ASEAN ministers, told a radio programme that the business environment and the recent alleged scams in Southeast Asia should not be connected.

He added that Hong Kong must strengthen its economic and trade cooperation with ASEAN countries.