A UN Food and Agriculture Organization (FAO) official said in Islamabad Thursday that an outbreak of bird flu reported to have killed millions of chickens has been contained in Pakistan, English-language newspaper The News reported Friday.

"So far, the information that we have is that the disease is contained, the virus is contained, but we have to be very careful, " Omar Salah, FAO representative to Pakistan, told reporters.

Pakistani Agriculture Minister Sardar Yar Mohammed Rind said there has been no cases of the H5N1 strain of bird flu in Pakistan. However, he said the country has been hit by the H-7 and H-9 strains less dangerous to humans.

Earlier reports said that in the past three months, between 1.5 million and 3.5 million chickens were killed by bird flu in farms around the southern port city of Karachi.

As a precaution, the Pakistani authorities have banned the transportation of chickens and other domestic birds inside the country.