KABUL, March 8 (Reuters) - Afghanistan will cull poultry after 13 new cases of the deadly H5N1 strain of bird flu were discovered, including some in the capital, a U.N. official said on Thursday.

Assadullah Azhari, the U.N. Food and Agriculture Organisation spokesman in Afghanistan, said the latest outbreak comprised six cases of home-raised poultry in the eastern province of Nangarhar, four in Kabul and three in eastern Kunar province.

"We collected samples from these areas and all tested positive," Azhari said. He added the government had not said how many birds would be culled. Quarantine and vaccination measures were also being used.

The World Animal Health Organisation (WHO) had already confirmed two outbreaks of H5N1 each in flocks of backyard poultry in Nangarhar and in turkeys in Kunar. The total number of cases discovered this year was now 17.

Last month, Afghanistan banned poultry imports to prevent the spread of the virus.

The H5N1 strain was found in poultry in at least four Afghan provinces last year, leading to the killing of thousands of birds, but there were no human deaths.

Afghanistan imports a large amount of poultry, mostly from Pakistan. The ban imposed also applies to other countries hit by H5N1, including Britain, Turkey and Indonesia.

The country lies at the junction of Central and South Asia and is on the migration route for several species of wild birds.

The virus has infected at least 275 people in 12 countries since 2003 and killed at least 167 of them in 10 countries, the World Health Organisation says.

Public health experts fear it could mutate into a form that people catch easily from one another.

AlertNet news is provided by