ISLAMABAD (AFP) - Pakistani authorities have found the deadly bird flu virus at two more poultry farms in the capital, bringing the number of outbreaks reported this week to five, officials said Friday.

The disease erupted at farms in Chak Shehzad, a suburb of Islamabad where the earlier three cases were discovered. Officials said there had been no cases of human infection by the H5N1 virus.

"The disease at the two farms killed 3,000 birds and we culled the remaining 4,000 chickens on Thursday after samples tested positive for H5N1," Agriculture and Livestock Ministry spokesman Mohammad Afzal told AFP.

Another 11,000 birds died from the virus or were slaughtered earlier this week at the other three affected farms.

"We have increased surveillance in the area and advised surrounding farms to immediately vaccinate their birds to prevent further spread of the disease," Afzal added.

The disease last appeared in April in northwest Pakistan and the southern port city of Karachi, but it was quickly controlled.

The authorities in March were forced to shut Islamabad Zoo and slaughter dozens of birds after the virus was found in peacocks and geese.