An Indonesian official has warned that a healthy chicken could be a carrier of the bird flu virus although it shows no symptoms of the illness, following a finding in West Java province, a report said Thursday.

Head of the West Java Animal Husbandry Office Rachmat Setiadi said the warning was made following the discovery of healthy chickens that tested positive with H5N1 virus from a serology test.

The test involved 20 chickens around the house of two dead bird flu victims in Batunggal, reported the major national newspaper The Jakarta Post.

Rachmat said only chickens and ducks are believed to carry the virus.

"The test has shown that four healthy chickens were infected with H5N1. We should be more cautious," he said Wednesday in the provincial capital of Bandung , some 150 km south of Jakarta .

Currently, people are only made aware of the danger of bird flu when chickens die suddenly in their neighborhood, but Rachmat said healthy chickens could also be carriers.

He said cases where healthy chickens were infected with bird flu had occurred not only in Bandung , but also in other cities and regencies. However, he did not name the cities or regencies.

He recommended that residents stop keeping chickens in their backyards or near their houses.

Source: Xinhua