Hong Kong  - Fears of a bird flu outbreak in Hong Kong were receding Monday after tests on all markets in the city of 6.9 million failed to find further traces of the H5N1 virus.

The former British colony went on bird flu alert Saturday after swabs taken at a market in the Shamshuipo district found traces of the virus that led to a deadly outbreak in Hong Kong 11 years ago.

The market was closed down, chickens from mainland China were banned and tests were ordered on all poultry markets in the city, a move which saw the sales of chickens plunge 30 per cent Sunday.

However, the government announced Monday that no traces of the virus had been found at any other market in the city or in farms in Hong Kong or in southern China.

Assistant director for agriculture Thomas Sit said investigations into the source of the virus were continuing and customs officers were checking if affected chickens were smuggled into Hong Kong.

Workers in face masks and protective suits Saturday killed 2,700 chickens at an infected market in a chilling reminder of the bird culls in the city in the 1990s.

Hong Kong was home to the first modern case of bird flu to jump the species barrier and infect humans in 1997 when the H5N1 virus killed six people and infected 12 others.

Since then, thanks largely to stringent checks and mass culls when any cases are discovered, there have been no further cases of humans infected by bird flu in Hong Kong despite regional outbreaks. (dpa)