Hong Kong's Chief Executive, Tung Chee-hwa, has admitted failings in the operation to slaughter the territory's 1.25 million chickens. The killing has run into a number of logistical problems which the authorities are now struggling to address. Scientists are now turning their attention to other animals to see if they are capable of carrying the dangerous "bird flu" virus which the slaughter of the chickens was intended to eliminate. From Hong Kong, Jill McGivering reports:

Mr Tung admitted there had been inadequacies in the government's slaughter of Hong Kong's chickens and said public concern about the way the operation was handled was justified. He was speaking after a special briefing of Hong Kong's Executive Council to discuss the crisis.

The operation to kill Hong Kong's chickens was supposed to take 24 hours, but five days later thousands of chickens are reported to be still alive. Officials said the scale of the killing was unprecedented and the operation was carried out by government staff with little or no experience of killing birds.

Hong Kong residents have reported seeing live chickens wandering close to public housing estates. The birds are thought to have escaped from nearby farms after surviving the gas used in the slaughter.

There have also been delays in disposing of the carcases of slaughtered poultry. In some areas rats, dogs and cats have been seen tearing open refuse bags and eating dead birds.

This has sparked fears that the virus could spread through other animals which have had direct contact with infected chickens. Hundreds of samples have now been taken from rats and dogs living close to one of Hong Kong's wholesale chicken markets.

The market was earlier declared an infected site after dead chickens there tested positive for the new virus. One official said if there were any positive tests amongst the samples from dogs and rats, the authorities would consider extending the slaughter beyond chickens.