By Yilei Sun and David Stanway

SHANGHAI (Reuters) - The ability of the coronavirus to spread is getting stronger and infections could continue to rise, China's National Health Commission said on Sunday, with more than 2,000 people globally infected and 56 in China killed by the disease.

National Health Commission Minister Ma Xiaowei, speaking at a press briefing, said knowledge of the virus was limited.

Ma said the incubation period for the coronavirus can range from one to 14 days, and that the virus is infectious during incubation, which was not the case with Severe Acute Respiratory Syndrome (SARS), a coronavirus that originated in China and killed nearly 800 people globally in 2002 and 2003.

Containment efforts, which have thus far included transportation and travel curbs and the cancellation of big events, will be intensified, Ma told a crowded news briefing on the second day of the Lunar New Year holiday.

The virus, believed to have originated late last year in a seafood market in the central Chinese city of Wuhan that was illegally selling wildlife, has spread to Chinese cities including Beijing and Shanghai, as well as the United States, Thailand, South Korea, Japan, Australia, France and Canada.

President Xi Jinping said during a politburo meeting on Saturday that China was facing a "grave situation", as health authorities around the world scrambled to prevent a pandemic.

On Sunday, China announced a nationwide ban on the sale of wildlife in markets, restaurants, and e-commerce platforms. Wild and often poached animals packed together in Chinese markets are blamed as incubators for viruses to evolve and jump the species barrier to humans.

Snakes, peacocks, crocodiles and other species can also be found for sale via Taobao, an e-commerce website run by Alibaba.

The U.S. State Department said it will relocate personnel at its Wuhan consulate to the United States and will offer a limited number of seats to private U.S. citizens on a Jan. 28 flight to San Francisco.

The World Health Organization this week stopped short of calling the outbreak a global health emergency, but some health experts question whether China can continue to contain the epidemic.

On Sunday, China confirmed 1,975 cases of patients infected with the new coronavirus as of Jan. 25, while the death toll from the virus has risen to 56, state broadcaster CCTV reported.

The outbreak has prompted widening curbs on movements within China, with Wuhan, a city of 11 million, on virtual lockdown, with transports links all-but severed except for emergency vehicles.

Health authorities in Beijing urged people not to shake hands but instead salute using a traditional cupped-hand gesture. The advice was sent in a text message that went out to mobile phone users in the city on Sunday morning.

CANCELLATIONS AND MISTRUST

China has called for transparency in managing the crisis, after a cover-up of the spread of the deadly SARS virus eroded public trust, but officials in Wuhan have been criticized for their handling of the current outbreak.

"People in my hometown all suspect the real infected patients number given by authorities," said Violet Li, who lives in the Wuhan district where the seafood market is located.

"I go out with a mask twice a day to walk the dog - that's the only outdoor activity," she told Reuters by text message.

The outbreak has overshadowed the start of the Lunar New Year, when hundreds of millions of Chinese travel at home and abroad to be with families, with public events canceled and many tourist sites shut.

Many cinemas across China are also closed with major film premieres postponed, slashing revenues. Theaters in the country took in just 1.81 million yuan ($262,167) from tickets on Saturday, a tiny fraction of the 1.46 billion yuan on the Lunar New Year Day in 2019, according to data from movie-ticketing company Maoyan.

Cruise operators including Royal Caribbean Cruises, Costa Cruises, MSC Cruises and Astro Ocean Cruises said that they canceled a combined 12 cruises that had been scheduled to embark from Chinese ports before February 2.

The newly identified coronavirus has created alarm because there are still many unknowns surrounding it, such as how dangerous it is and how easily it spreads between people. It can cause pneumonia, which has been deadly in some cases.