Hong Kong  - Hong Kong is at a "higher risk" of an outbreak of swine flu because the city of 7 million is so densely populated, its leader Donald Tsang said Tuesday.

Beijing-appointed Tsang made the remark after government officials held a teleconference with counterparts in Macau and the neighbouring southern Chinese province of Guangdong.

The former British colony has been on alert for signs of the virus and Monday announced that three people tested for swine flu had been given the all-clear.

Tsang urged members of the public to cooperate with officials in fighting the flu strain, which may have claimed up to 149 lives in Mexico with more than 20 of those cases so far confirmed.

A government steering committee met Tuesday morning to decide if further measures were needed after the World Health Organization raised its alert level. It was expected to announce its decisions later Tuesday.

High-rise Hong Kong has an elaborate system in place to guard against disease after previous outbreaks of bird flu and severe acute respiratory syndrome (SARS), officials said.

Nearly 300 people died and around 1,800 were infected when SARS spread from China to Hong Kong in 2003. Six people died and 12 others were infected in a bird-flu outbreak in Hong Kong in 1997. (dpa)