Over 300 white-winged ducks in Vietnam's capital city Hanoi have died with unidentified causes over the past few days, while bird flu continues to spread in the country.

Specimens from the fowls raised by two households in the city's Thanh Tri district are being tested for bird flu viruses. The local veterinary agency has culled all fowls in the affected two flocks and disinfected affected area, local newspaper Labor reported Tuesday.

Bird flu, starting to strike Vietnam in December 2003, has hit 16 Vietnamese cities and provinces nationwide since early May, according to the Department of Animal Health under the Vietnamese Ministry of Agriculture and Rural Development.

Source: Xinhua