Bird-watching activities are continuing in Beijing even as Chinese and overseas scientists suggested the H7N9 bird flu virus currently affecting people in the country was one of the most lethal that doctors and medical investigators had faced in recent years.

Animal surveillance officials have found the virus in live poultry at poultry markets and, notably, a wild pigeon, the Ministry of Agriculture said.

The poultry business has been seriously undermined by the epidemic, whose source of infection and transmission modes remained unclear.