Vietnam said two children who died of bird flu this month had tested positive for the H5N1 strain, taking to three the number of deaths from the latest outbreak of a virus that killed 24 people across Asia earlier this year.
"It is the H5N1 virus," said a doctor at the Hanoi Institute of Hygiene and Epidemiology on Tuesday.
Initial tests by the institute had shown the presence of the H5 component in the children from the northern province of Ha Tay, and further tests confirmed the presence of the N1 sequence.
The two children were a 4-year-old boy who died on August 2 and an 11-month-old girl who died on August 4. Vietnam's first confirmed fatality this month was a 25-year-old woman from the southern province of Hau Giang.
"It's not a surprise," said Hans Troedsson, Vietnam representative for the World Health Organisation, when told of the test result.