Washington, Jan 6 (IANS): The internal border between the former British colony of Hong Kong and the rest of China will open for the first time in three years on Sunday, with tens of thousands of people expected to undergo Covid-19 test required to move back and forth between the two sides, according to a media report.

The move comes after China last month abandoned the rolling lockdowns, mass surveillance and quarantine camps of its zero-COVID policy in a bid to kickstart its flagging economy, RFA reported.

Authorities there will be lifting travel bans and opening its ports and airports across the country at the same time.

"This doesn't just pose a deadly threat to the 1.4 billion people in China; it will also affect its neighbors," Hong Kong current affairs commentator To Yiu-ming wrote.

"Hong Kong won't be able to bear the brunt [of an expected influx of people from mainland China] unless it uses its pandemic policy to protect the interests of Hong Kongers."

"Although the exact numbers are unknown, the outbreak in China has been enough to cause social panic, because it is obvious to everyone that the medical system is on the verge of collapse, with funerals and cremations booked to capacity," To said, RFA reported.

He said now appears to be a very bad time to open China's borders.

"What's even more incredible is ... they are opening the borders at a time when COVID-19 is ravaging the country, with many reports of ground-glass opacity in patients' lung scans," he said, in a reference to a higher likelihood of pneumonia, RFA reported.

"It's natural that people are trying to escape and seek assistance... and for them, it's a great time to come to Hong Kong to seek medical treatment or buy medicine," he wrote.

While quarantine-free travel across the border will resume, it will be done in a "gradual and orderly manner," China's Hong Kong and Macau Affairs Office said in a statement on Thursday.

Under the new rules, anyone entering the rest of China from Hong Kong will need to show a negative PCR test from the past 48 hours, with this requirement waived for those coming in from Macau who haven't traveled outside the city in the previous seven days, RFA reported.

Anyone who declares they have a fever on their customs health declaration form will be tested for COVID-19, but otherwise will be waved through. Anyone found to have mild sickness or an asymptomatic infection will be asked to self-isolate on arrival and seek medical treatment, but this is only a recommendation, the statement said.