HONG KONG - HONG Kong was placed on a new flu alert after a mainland Chinese man suspected of carrying H1N1 flu was found to have stayed in a hotel in the city for two nights, authorities said late on Monday.

The 59-year-old man, a resident of China's Guangdong province, arrived in Hong Kong from South Korea on Wednesday after travelling to the United States and Canada, a government spokesman said in a statement.

The man stayed two nights at a hotel in the city's Mong Kok district before boarding a train to Guangzhou on Friday.

He was detained at the customs checkpoint in Guangzhou after developing a fever while on board the train and diagnosed with the A(H1N1) virus following a preliminary test, China's health ministry said.

Flu experts are concerned that the latest case could trigger a community outbreak in Hong Kong.

The city's Centre for Health Protection has started tracing people who may have been in contact with the patient, including staff members at the hotel and fellow passengers on board the Guangzhou-bound train.

Hong Kong has identified three confirmed cases of imported swine flu since early May. -- AFP