"I am going back because I don't have to undergo quarantine anymore," an elated Tan told AFP, clutching luggage containing a few boxes of fever medication for family.

Tan, 23, was planning to travel to Shenzhen just across the border from Hong Kong and then take a connecting flight to her hometown of Yangzhou in eastern China, a journey that until recently would have meant weeks in mandatory isolation first.

China lifted quarantine rules for all international visitors on Sunday, ending almost three years of self-imposed isolation.

On the same day, the border between mainland China and Hong Kong also did away with most restrictions. Around 60,000 people are now allowed to travel each way daily.

On Sunday morning there were large crowds at the Lok Ma Chau border crossing heading north, but noticeably fewer people heading south into Hong Kong.

With the Lunar New Year two weeks away, many said they were going for family reunions.

Chinese student Galen Liu said he had been studying for a doctorate in Europe, making a return home all but impossible until now and leaving him feeling "helpless".

Two weeks ago he flew into Hong Kong and waited for the border to reopen so he could reunite with his parents and sister in neighbouring Guangdong province.

"I am really excited," Liu told AFP. "Now I can finally go home and I don't need to take a flight -- I can just cross the border overland."

Liu was carrying medicine for family, most of whom he said had been recently infected after China abruptly abandoned its strict zero-Covid strategy.

Cases have soared in the world's most populous nation, with hospitals and morgues under huge pressure, although authorities have given little data on infections or deaths.

A housewife surnamed Dong, who was returning to Hong Kong from Shenzhen, was stoic about the explosion of cases.

"It's inevitable when the restrictions are relaxed. People have to be able to move around or the economy cannot grow. We must treat it more calmly," she said.

Those using the Hong Kong-mainland border must have proof of a recent negative test, a requirement Beijing has criticised other nations this week for imposing on travellers from China.

Mainland entrepreneur Alex Zeng was among those headed into Hong Kong, a city that long served as a business gateway to China before it was cut off by Covid.

The sports equipment manufacturer said he planned to attend an exhibition there before travelling overseas for much needed meetings with clients.

"It was quite inconvenient when I could not travel and meet my customers face to face," Zeng told AFP.
"When my clients wanted to check out a sample, we could only do it via video link."

Hong Kong's economy is in dire straits, mired in recession and desperate for crowds to return. Prior to the pandemic, mainlanders accounted for about three quarters of arrivals.

An 80-year-old traveller surnamed Liu said he was returning to Hong Kong to celebrate the Lunar New Year with family.

"I hope the procedure can be further simplified, like scrapping the test result requirement," Liu told AFP. "It's a bit complicated for an 80-year-old man like me."