Photo:Sina Weibo

The number of quarantined patients suffering from an unknown form of  pneumonia has jumped to 59 with seven in critical condition in Wuhan, Central China's Hubei Province. Health authorities have ruled out the possibility that SARS or MERS is to blame, according to an official statement released Sunday. 

A few patients who were infected worked at a local seafood market, but early investigations showed no signs of human-to-human transmission, according to the statement. So far, authorities have ruled out the flu, avian flu, or adenovirus infection as possible causes. 

Singapore reported its first case of the pneumonia over the weekend, which might be linked to Wuhan, according to media reports. 

Hong Kong authorities reported on Sunday that within 24 hours, public hospitals admitted seven patients who had been to Wuhan in the past two weeks and were experiencing fever, respiratory infection, and pneumonia-like symptoms, according to a statement on the Hong Kong Special Administrative Region's website.

Hong Kong and Singapore have taken precautions against the unknown virus.

Temperature screening measures have been implemented at the Singapore Changi Airport and thermal imaging is underway at the Hong Kong International Airport.

Netizen speculation on Weibo blamed SARS, first diagnosed in 2002, which caused panic and forced authorities to address public concerns. So far, Wuhan police have arrested eight people for spreading rumors that the pneumonia was linked to SARS. 

The World Health Organization (WHO) said on Twitter on Sunday that it is monitoring the situation in Wuhan and is in contact with national authorities in China.