The group's spokesman Major Asad Ali confirmed a blood sample sent to Islamabad tested positive on Monday. Authorities at the farm have killed around 4,000 birds since the confirmation.
However, following the receipt of the report, the employees of the farm were cleared of any contact with the virus. So far the flu has been confirmed at the two farms in the city.
Surveillance at hundreds of other farms that supply poultry products to the city's 15 million people has been tightened and samples from other farms in the area were also taken for tests, according to reports. Hundreds of birds at a poultry farm in the Gadap area of the port city were culled on Friday last following confirmation of reports of an outbreak of bird flu.
Personnel of the poultry and livestock and agriculture departments of the provincial and city governments killed the birds and buried them in a dry well in a farm on the instructions of Sindh Poultry Director Dr. Ali Akbar Soomro.
The H5N1 virus has been circulating in Asia since 1997 and it first appeared in Pakistan around two years ago.
