World Health Organisation officials say they are trying to determine why the bird flu outbreak in Turkey has spread so quickly among humans, especially children.

Bird flu in humans appears to be spreading in Turkey, with three people in Ankara testing positive for the deadly H5N1 strain of bird flu in preliminary tests, representing the first suspected cases outside the eastern city of Van.

A Turkish teenager who died of bird flu most likely succumbed to the deadly H5N1 strain of the virus, a senior World Health Organisation official said today.