Chinese authorities and the World Health Organization say a new strain of coronavirus is behind the outbreak of pneumonia in the central city of Wuhan, which has erupted just ahead of the Lunar New Year, the country's biggest festival.
Health officials say the strain does not appear as lethal as some other strains of coronavirus such as severe acute respiratory syndrome (SARS), which killed nearly 800 people worldwide during a 2002-03 outbreak that also originated from China.