Jakarta (ANTARA News) - International airports in Indonesia will be asked to specially examine passengers from certain provinces in China as an anticipatory measure against the spread of H7N9 bird flu virus, a health ministry official said.

"Big airports are requested to examine passengers from several affected provinces in China. Not all passengers from China but only from certain provinces will be affected," the director general of contagious disease control and environment health of the ministry of health, Tjandra Yoga Aditama, said here on Wednesday.

According to China`s news agency Xinhua 28 people had been affected by the virus and nine of them had died until Wednesday.

Tjandra said increasing deaths from the virus had prompted his office to take anticipatory measures and issue a circular to international airports and seaports asking them to check passengers from certain provinces in China such as Shanghai and Zhejiang.

"I signed the circular yesterday (Tuesday, March 9). It would take two to three days before it reaches the airports and seaports," he said.

Before the H7N9 virus did not attack human beings but only poultry so panic came when someone was found dead because of the virus, he said.

Tjandra however said that based on laboratory tests oseltamivir and zanamivir that have so far been used to handle the H5N1 bird flu virus could also be used to deal with the H7N9 virus.

"But in general we cannot as yet confirm its effectiveness as the number of patients is still small and the disease has just broken out in the past several months," he said.