HONG KONG - Primary and secondary schools and preschools in Hong Kong will remain closed until March 2 while civil servants will be allowed to work from home until Feb 9, the city's Chief Executive Carrie Lam Cheng Yuet-ngor announced on Friday.

The new arrangements are among an additional round of measures announced by the government hours after the World Health Organization declared the novel coronavirus outbreak a Public Health Emergency of International Concern.

Lam said that the SAR government and educational authorities would continue to monitor the situation and assess whether it is safe to resume classes on March 2.

She said that heads of various government departments should make work arrangements in a flexible manner while guaranteeing basic public services to local residents.

The government also announced that local residents who had been to Hubei province in the past 14 days would be placed in a quarantine center for observation even if they are asymptomatic. Hubei's capital, Wuhan, is the epicenter of the epidemic.

As of Friday morning, Hong Kong has confirmed 12 cases of novel coronavirus infection.

When asked if the government would consider locking down the city, Lam said such a move would run contrary to the WHO's recommendations.

WHO Director-General Tedros Adhanom Ghebreyesus on Friday stressed that the organization disfavored or even opposed imposing travel or trade restrictions on China.

But Lam said inbound travelers would be required to submit a health declaration form at Lo Wo Port and Shenzhen Bay Port starting from Saturday.

As of 1 pm Friday, 48 Hubei visitors who had recently visited Hong Kong were identified. Fifteen of them had left the city, while the remaining 33 have been put in quarantine.

Lam also said 200 electronic devices would be used to track those who have been asked to quarantine themselves at home.