Hospital officials in Hong Kong raised their alert level to "serious" on Saturday as a mystery viral pneumonia outbreak in mainland
China continued to spread.
The infection was first reported on December 31 in Wuhan, a central Chinese city with a population of over 11 million -- leading to online speculation about a resurgence of the flu-like SARS virus that killed hundreds of people in 2002-2003.
The number of reported cases has now risen from 27 to 44, with 11 people listed in serious condition, according to China's public health watchdog.