The three latest outbreaks were detected in the northern central Thanh Hoa Province and the southern Tra Vinh Province, said Nguyen Van Long, deputy head of the Animal Health Department under the Ministry of Agriculture and Rural Development. Around 2,670 poultry have either died or been culled across these areas as a result, Long said.

Avian flu outbreaks have also been detected in Hanoi, the nearby Bac Ninh Province and Nghe An that borders Thanh Hoa.

Factors that heighten the chances of avian flu outbreaks across Vietnam include dense poultry population, extreme weather patterns and unsanitary meat trade and butchering practices, said Minister of Agriculture and Rural Development, Nguyen Xuan Cuong, at a conference on preventing diseases among poultry and cattle last week.

Earlier this month, the agriculture ministry called on localities nationwide to step up preventive measures against bird flu outbreaks in response to recent reports by World Organization for Animal Health (OIE) stating outbreaks were reported in 11 countries and territories this year.

Vietnam has around 460 million poultry, according to Animal Health Department. Around 133,000 had to be culled last year due to avian flu outbreaks.

Two avian flu virus strains, H5N6 and H5N1, were detected during the current outbreaks. They both spread from poultry to humans through contact with infected faeces or other bodily fluids, and are potentially fatal.

Vietnam has seen avian flu outbreaks here and there starting in 2003. The disease has since killed at least 65 people in the country. No human deaths have been reported in the last two years, but occasional outbreaks have led to thousands of birds being killed.