The number of Vietnam's confirmed bird flu deaths has risen to four, the World Health Organisation said, while a hospital in the south of the country said on Saturday it had two very sick patients with bird flu symptoms.
The UN health agency, which is helping Vietnam battle the fast-spreading disease, said a five-year-old boy, from Nam Dinh province, died on January 8 from bird flu. Nam Dinh is about 100 km (60 miles) south of the capital Hanoi.
"WHO now counts four confirmed cases of H5N1 in Vietnam," the agency said in a statement issued late on Friday, referring to the bird flu virus.
South Korea, Japan and Taiwan have also reported outbreaks of bird flu but Vietnam has been the hardest hit.
The cases have raised fears of a new deadly epidemic sweeping out of the region that saw an outbreak of Severe Acute Respiratory Syndrome spread around the world last year and kill about 800 people.
All of Vietnam's confirmed cases, plus eight other human flu deaths under investigation, were from the north. But a hospital in the southern province of Kien Giang said it was treating a woman and man, both in their twenties, for serious influenza infection.