The World Health Organisation said it is in ongoing contact with authorities in China over an unidentified outbreak of viral pneumonia in the central city of Wuhan, amid concern it may have been transmitted from animals. Wuhan health authorities on Tuesday said 27 people – most of them stallholders at the Huanan Seafood Wholesale Market – had been treated in hospital, with seven said to be in serious condition. Pathology tests were under way to try and identify the virus, officials said. Hong Kong medical authorities were also on alert. Wuhan authorities ordered the closure of the market on Wednesday. Local media said the market sold other animals, including birds, raising concern after the 2002-03 outbreak of severe acute respiratory syndrome (Sars) in China killed several hundred people and is thought to have jumped from animals to humans. Officials in China and at the WHO said the virus in Wuhan had yet to be identified. “Investigations are still being carried out and authorities cannot yet confirm what pathogen is causing this illness,” said Paige Snider, a senior adviser with the WHO in China, adding that the organisation had been in contact with Chinese authorities. “There are many potential causes of viral pneumonia, many of which are more common than severe acute respiratory syndrome coronavirus. WHO is closely monitoring this event and will share more details as we have them,” she said. Online news outlet Hongxing, an affiliate of Chengdu Economic Daily , reported late on Tuesday that the market sold other wildlife, including pheasants and snakes. It also said the organs of rabbits and other animals were found in the market. A seafood vendor surnamed Sun confirmed the Hongxing report, saying such animals were available for sale in the market. Medical authorities in Hong Kong , which is about four hours from Wuhan by high-speed train, said late on Tuesday they had stepped up border screening and put hospitals in the city on alert. “The situation in Wuhan is unusual, and we are not sure about the reasons behind the outbreak yet,” Hong Kong’s Secretary for Food and Health Sophia Chan Siu-chee said after a meeting with officials and experts on New Year’s Eve. “Since we are now in the holiday season, and Hong Kong has close transport ties with Wuhan, we must stay alert.” Yuen Kwok-yung, a microbiologist at the University of Hong Kong, said that although the Wuhan case had similarities to the 1997 outbreak of bird flu and the Sars epidemic, there was no need for people to panic though they should remain alert. “There are chances that the virus was transmitted from animals to humans, but so far the authorities have not identified the virus,” he said on Tuesday before the Hongxing report. Law enforcement officers wearing face masks were on guard outside the market on Wednesday morning as seafood vendors were allowed to remove their stocks, the official Yangtze Daily reported. The city’s health and commerce regulators issued the notice to close the market. “After considering the municipal health commission’s report about the current pneumonia situation in the city, it is decided that Huanan seafood market will be closed for sanitation and renovation … the date for reopening will be announced later,” the notice said. News of the outbreak in Wuhan came to light after an urgent notice from the city’s health department, which told hospitals to report further cases of “pneumonia of unknown origin”, started circulating on social media on Monday night. The 2002-03 Sars epidemic infected more than more than 5,300 people and killed 349 in mainland China. In Hong Kong, 1,750 people were infected and 299 died. According to the WHO, the Sars coronavirus is thought to be an animal virus from an as-yet-uncertain animal reservoir, perhaps bats, that spread to other animals and first infected humans in Guangdong, near Hong Kong, in late 2002. Purchase the China AI Report 2020 brought to you by SCMP Research and enjoy a 20% discount (original price US$400). This 60-page all new intelligence report gives you first-hand insights and analysis into the latest industry developments and intelligence about China AI. Get exclusive access to our webinars for continuous learning, and interact with China AI executives in live Q&A. Offer valid until 31 March 2020.