Six months after Thailand was declared free of the deadly bird flu virus, Thailand's agriculture ministry has confirmed a fresh bird flu outbreak on a backyard farm in the north.

Two hundred and seventy birds were slaughtered in Sukhothai province after the H5N1 strain of avian influenza was found in a dead chicken, though there are not reports of any people sick from it. Investigations are underway to determine whether the outbreak was caused in Thailand or had its origin in a neighbouring country.

Monitoring the surrounding area for 21-days, Thailand will inform the World Organization for Animal Health about any new developments. Thailand, which is the world's fourth-largest exporter of poultry, has already begun the slaughter of millions of birds, in a bid to halt the spread of the deadly virus that led to a suspension of its' frozen poultry exports since 2004.

So far, according to World Health Organisation figures, the H5N1 strain has killed 245 people worldwide since late 2003, leading experts to fear it could mutate into a form easily transmissible between people, thus sparking a deadly global pandemic.