Vietnam has detected bird flu on three farms near the Chinese border, the second such finding in the past few days, an animal health official said on Saturday.
Health workers slaughtered 157 chickens and ducks after farmers said 30 birds died on March 19 on three farms in Cao Bang province, said Dang Quang Binh, head of the provincial Animal Health Department.
"We sent samples for testing and on March 25 the results showed H5 was found in poultry samples from the three farms," Binh told Reuters by telephone from Cao Bang, 270 km (167 miles) north of Hanoi.
He was referring to the H5 subtype avian flu virus.
No further tests were likely be done to confirm if the strain was H5N1, which has killed 42 people in Vietnam since late 2003.