Hong Kong chicken flu sparks mass spring clean

By CNN's Hope Ngo

HONG KONG, China (CNN) -- The Hong Kong government has launched a massive market clean up to avert an outbreak of 'chicken flu'.

The government stepped up its campaign after local media reported that more birds were found dead at a fourth live fowl stall.

Secretary for the Environment and Food Lily Yam denied criticism that the government had again reacted too slowly to contain the virus.

"We have to act on the basis of confirmatory evidence, and in a situation like this, there are always people who would come out and (say) the action is too slow," Yam told reporters late Thursday.

"If we have acted earlier, equally people would come out and say we are in panic," she said.

The illness was rediscovered in Hong Kong on Wednesday, when nearly 800 chickens were killed by a strain of the H5N1 virus which officials say is not harmful to humans.

More than six thousand birds have been destroyed at public markets where the sick chickens were found in an attempt to contain the virus.

The government culled the territory's entire 1.4 million beak bird population in 1997 in an attempt to contain a similar outbreak of avian flu. Six people who were infected by that strain of the virus died.

The outbreak triggered international concern, and had a devastating effect on the former British colony's restaurant and tourism industries.