Hong Kong leader Carrie Lam announced that 10 out of 13 border crossing with mainland China have been closed, in a bid to curb the coronavirus.
Ms Lam stopped short of fulfilling the demand of some doctors that she shutter the entire frontier.
Such a move would be “inappropriate and impractical”, she said previously.
But the new restrictions are a step up from measures she had already imposed that halted ferry and rail crossings.
Some 2,400 doctors went on strike in Hong Kong to demand the border with China be closed.
The medics also wanted better distribution of face masks, sufficient isolation wards for patients and guaranteed supplies.
So far 362 people have died of the disease, according to John Hopkins University, of more than 17,400 infected. Nearly 500, however, have recovered.
A string of countries and individual airlines have suspended travel to China because of the outbreak, while the Maldives have banned travellers from China from entering.
The restrictions come despite the World Health Organisation saying flight cancellations were not necessary.
Beijing has accused the US, in particular, of fostering a climate of fear by its reaction to the outbreak.
