The number of confirmed cases, which emerged in the central Chinese city of Wuhan, soared to more than 4,500 by Monday -up from 2,835 from the previous day, health authorities said.

High-speed rail and intercity through train services will be suspended from midnight Thursday, Lam said, adding that the number of flights to the mainland will be halved and personal travel permits for mainland Chinese to Hong Kong suspended.

“I thank the central government for supporting our work in this aspect (suspending cross-border transport) and the relevant mainland ministries and commissions for cooperating with us,” Lam told reporters, according to Reuters.

She also urged Hong Kong residents to return from the mainland as soon as possible and quarantine themselves at home for 14 days.

With financial markets in the city set to reopen Wednesday after the Lunar New Year holiday, Lam was joined at the news conference by Health Secretary Sophia Chan and Commerce Secretary Edward Yau, both of whom also wore masks.

Chan said Hong Kong had eight confirmed cases, while 100 patients were in quarantine.

The former British colony has been roiled by more than seven months of anti-government protests that have seen more than 7,000 people arrested.

On Tuesday, the judiciary announced that all court hearings scheduled from Wednesday to Feb. 2 would be adjourned.

Beijing-backed Lam also defended her decision not to close the entire border amid the outbreak, saying such a move would prevent the return home of many city residents who commute daily.