JAKARTA - A senior official overseeing animal husbandry in Indonesia's East Java province confirmed Tuesday that the cause of the recent deaths of 11,000 ducks in the Kediri regency was avian influenza.

The confirmation came up after the regency administration received results of examinations on bio molecular samples of the ducks taken last month.

"We knew the results after received results of examinations conducted by a laboratory in Malang, East Java. Results from the other examination conducted by a laboratory in Yogyakarta had not been released,"said Sri Suparmi, head of Kediri regency animal husbandry supervisory body.

She said that the type avian flu attacked the ducks in the regency was different from the other ones that attacked chickens and birds. She added that the virus attacking the ducks has gone through genetics changing.

According to Suparmi, the virus attacking the ducks was derived from H5N1 with genetic structure identified as Clade 2.1. Now the virus had already developed into Clade 2.3.

"Field observation efforts to identify factors that have changed the virus genetics code are underway at the moment,"she was quoted by the Kompas.com.as saying.

The remaining ducks have not been vaccinated as local husbandry office doesn't have vaccine to prevent the clade 2.3 virus.

People in the regency were told not to panic about the finding of new avian flu virus. They were advised to wash hands with soap and use masker when they pass through areas identified as harmed by the virus.