Updated at 6.21pm: Despite growing fears about the spread of bird flu, Health secretary York Chow Yat-ngok said on Wednesday there was no need yet for Hong Kong to slaughter all live chickens. Dr Chow?s comments follow the recent discovery in Hong Kong of a chicken, smuggled from the mainland, and four wild birds which had all died from the H5N1 strain. Tests are also being done on another dead chicken suspected of having bird flu. The fowl was discovered on Saturday in a street in the suburban Tuen Mun area. But the Health Secretary stressed that the discovery of the disease in these birds still did not mean all live chickens should be slaughtered. ?Since these two chickens, one is a stray chicken and the other is actually from a backyard farm, we feel that our current chicken farms in Hong Kong are still well protected,? he said. But Dr Chow said the authorities would slaughter all chickens in a particular farm if any of its flocks was found to have been afflicted with bird flu. ?And if there is more than one chicken in our farms that are infected, in our licensed farms, then we have to sacrifice all the chickens in Hong Kong. That was the policy that we established a long time ago,? he added. The government has tightened rules to ban people from keeping live poultry at home or in backyards. People breaching the new law, which will come into effect on Monday, will be fined between $50,000 to $100,000 upon conviction. ?I would like to appeal to anyone keeping chickens in their home to try to call our Agriculture, Fisheries and Conservation Department so that we can collect the chickens for them,? Dr Chow urged. He said the new law was important as health authorities had difficulty maintaining the hygiene of backyard farms. ?It is very difficult to ensure the vaccine works properly in a lot of the backyard farms, particularly as some of the chickens are kept more than a long time, so they may be actually more than three or four months, and the vaccine may not be working after a certain period of time,? explained Dr Chow. ?More important, the segregation of chickens from the wild birds has been properly done in our chicken farms but not in our backyard farms or in the homes that kept poultry. So it is very important that we have to ensure that only licensed farms are allowed to keep chickens,? he said.