WUHAN, China — China's central government said on Monday that the nationwide total of confirmed infections from a deadly respiratory virus had risen to 2,744, with 769 new cases coming to light.

However, it said no new deaths were confirmed outside of Hubei province, which had earlier reported 24 new fatalities to bring the national total to 80 dead.

China has locked down the hard-hit province of Hubei in the country's center, an unprecedented operation affecting tens of millions of people and intended to slow transmission of the respiratory virus.

Its ability to spread appears to be "getting stronger" though it is "not as powerful as SARS", top Chinese health officials said at a press conference.

A working group chaired by Chinese Premier Li Keqiang to tackle the epidemic decided to extend the Spring Festival holiday originally scheduled to end on January 30 "to reduce population flows," alongside unspecified changes to the starting dates of schools, state news agency Xinhua reported.

The previously unknown virus has caused global concern because of its similarity to the Severe Acute Respiratory Syndrome (SARS) pathogen, which killed hundreds across mainland China and Hong Kong in 2002-2003.

Outside the epicentre, Shandong province and four cities -- Beijing, Shanghai, Xi'an and Tianjin -- announced bans on long-distance buses entering or leaving, a move that will affect millions of people travelling over the Lunar New Year holiday.

The populous southern province of Guangdong, Jiangxi in the centre, and three cities made it mandatory for residents to wear face masks in public.

Originating in Hubei's capital of Wuhan, the virus has spread throughout China and across the world -- with cases confirmed in around a dozen countries including as far away as the United States.

The US State Department said Sunday it was arranging a flight from Wuhan to San Francisco for consulate staff and other Americans in the city.

France's government and the French carmaker PSA also said they planned to evacuate staff and families, who will be quarantined in a city in a neighboring province.

Japan is coordinating with Beijing to swiftly evacuate its citizens, Prime Minister Shinzo Abe said.

Saudi Arabia asked its nationals present around Wuhan to contact its embassy for evacuation, while Jordan said it had obtained permission from Beijing to move its citizens from the city out of the country.

FEAR IN WUHAN

Instead of New Year revelry, Wuhan has been seized by an eerie calm that deepened on Sunday as new restrictions banned most road traffic in the metropolis of 11 million.

Loudspeakers broke the silence by offering tips slathered with bravado.

"Do not believe in rumors. Do not spread rumors. If you feel unwell, go to the hospital in time," the message said.

"Wuhan is a city that dares to face difficulties and keeps overcoming them," the female voice added, mentioning the deadly 2002-03 SARS epidemic and 1998 Yangtze River flooding.

The health emergency has overwhelmed Wuhan's hospitals with patients, prompting authorities to send hundreds of medical reinforcements, including military doctors, and start construction on two field hospitals.