HANOI - BIRD flu has resurfaced in poultry in northern Vietnam after many months without any cases, killing ducks and chickens at two farms, a state-run newspaper reported on Sunday.

Animal health officials confirmed on Saturday the H5N1 virus had killed several birds among a flock of more than 100 ducks in Thai Nguyen city, 80 km north of Hanoi, the Ho Chi Minh City Communist Youth league-run Tuoi Tre newspaper said.

Officials had also detected the virus in dead chickens at a farm in the same city and nearly 4,200 chickens had been slaughtered to prevent the virus from spreading, the report said without giving a timeframe.

Deputy Health Minister Trinh Quan Huan said this week that there was a very high risk of bird flu returning during the winter and spring in northern Vietnam. The H5N1 strain seems to thrive best in low temperature.

Five Vietnamese have died of bird flu so far this year out of six reported H5N1 infections and all were found in northern Vietnam during the first quarter of the year.

The H5N1 strain has killed 247 people globally among the 391 confirmed cases of infection since 2003, according to the World Health Organisation.

Vietnam has 106 infections, the second highest number of cases among 15 countries with known human cases after Indonesia. -- REUTERS