An unidentified worker looks on from a chicken farm sealed by authorities in a suburb of Islamabad; notice says "Restricted area due to bird flu"

Pakistan officials have confirmed a new outbreak of the deadly H5N1 strain of bird flu at a poultry farm near the capital, Islamabad.

A spokesman for the Food, Agriculture and Livestock Ministry says test results Friday confirmed earlier suspicions that the virus was present at a farm in Tarlai, a village on the outskirts of the capital.

The spokesman says at least 15,000 birds have been culled there and five other farms.

Pakistani officials confirmed the first outbreak of the H5N1 strain of bird flu in the northwest of the country last month. So far, there have been no reported cases of human infections.

Other countries bordering Pakistan - Iran, India and Afghanistan - have also reported cases of bird flu.

Some information for this report was provided by AFP and AP.