U.N. officials have confirmed a new outbreak of the virulent H5N1 strain of bird flu in Afghanistan.

A spokesman for the U.N. Food and Agriculture Organization (FAO) said Thursday samples collected from poultry in the Nangarhar and Kunar provinces and in the capital of Kabul have all tested positive.

The statement said the Afghan government has begun quarantines, slaughtering poultry and other preventative measures to curtail the outbreak, but did not give more details.

Afghan Health Ministry authorities confirmed cases of H5N1 in Nangarhar last month and authorized similar measures at the time.

The deadly strain of bird flu virus has killed at least 160 people worldwide since 2003.

It currently cannot be transmitted among humans, but scientists fear that if the virus mutates, it could cause a worldwide pandemic.

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