Tang, a Hong Kong resident in his 70s, only learned of the mandatory quarantine period as he was crossing the border to Shenzhen on Saturday morning to buy a train ticket.

He told immigration officers he wanted to make a U-turn.

“I said I didn’t want to cross the border now, but they said I must,” he said.

Tang returned to Hong Kong a couple hours later and was put under the mandatory quarantine scheme.

He was given a copy of his quarantine order and hand outs about health and hygiene tips.

Under the scheme, locals will be confined to their homes for 14 days, while non-locals will stay at hotels or the government’s quarantine centres.

Those violating the order face a maximum fine of HK$25,000 (US$3,220) and six months in jail.

The government said earlier those under quarantine must return to their homes or hotels within two hours of passing through immigration, but no officer would be escorting them.

Instead, officers would call the person to check they had arrived.

A 55 year-old media worker, surnamed Cheung, returned from Shenzhen on Saturday.

He said he was told to monitor his body temperature and that government officers could conduct random spot checks at his home.

“I will ask my family to buy me food and I’ll stay home,” he said.

Cheung described the latest policy as “neither here nor there”.

“They should have just closed down all the ports,” he said.

A 79 year-old Shanghai resident with a permit to stay in Hong Kong for two weeks that is valid for three months explained that she made a round-trip to mainland China to renew her stay in the city.

The woman, who declined to be named, said the authorities should scrap the two-week stay limit so she would not have to cross the border frequently.

“It increases my chances of being infected or spreading the disease,” she said, adding she stayed in Hong Kong to take care of her older sister, who had undergone surgery.

Dozens were also seen leaving the city via the port, including a cross-border couple in their 30s.

The man, a Hong Kong resident who wished not to be named, said his wife is from Huizhou and has to return to the mainland as her permit to stay in the city expires on Saturday.

He said it was likely the last he would see his wife for a few months.

“Before the epidemic passes, I don’t think they will issue the permit again,” he said.

“What can you do? This is what being a Hong Kong-mainland couple is like.”

He also said the latest quarantine measures were reasonable, as they were needed to protect Hong Kong residents.

A 61-year-old Hong Kong resident headed for Dongguan, surnamed Li, said he had no plan to return to Hong Kong unless he needed medical services.

Li, a factory owner, said he would stay in a company dormitory and was not too worried with the quarantine measures.

“It is not a big problem, as they allow you to come back [to Hong Kong],” Li said.

“If I feel ill, I will return, if not I will stay [on the mainland].”

Chief Executive Carrie Lam Cheng Yuet-ngor, who announced the quarantine measures on Wednesday but was absent from a government briefing of its details on Friday, was seen at Shenzhen Bay Port on Saturday afternoon.

Lam did not speak to media on site.

On Friday, almost 96,000 people entered Hong Kong, including 76,899 locals and 12,746 mainland Chinese visitors.