The two — a 41-year-old man and 26-year-old woman — were among five members of the same family who became sick after returning from a trip to the town of Marivan, close to their home in the northwestern city of Kermanshah.
The three surviving relatives were in hospital and one of them remained dangerously ill, the official, who spoke on condition of anonymity, told Reuters. It was not clear when the brother and sister died.
Samples have been sent to international laboratories for further tests, and if the initial results are confirmed, these would be the first human bird flu deaths in Iran.
Confirmation of H5N1 could deal a major blow to Iran’s poultry industry. The Union of Chicken Meat Farmers says the industry employs 600,000 people directly but as many as 3 million people are dependent on it.
“They had all returned from a trip to the town of Marivan when they fell ill with symptoms of staphylococcal pneumonia,” the official told Reuters, adding that the brother and sister had later tested positive for H5N1.
A third family member, aged 30, had slipped into a coma in hospital in Kermanshah, which is 100 km (60 miles) from the Iraqi border in the mountainous Kurdish territories of Iran.
The Islamic Republic first detected cases of bird flu inside the country in February, when the virus was found in wild swans.
All Iranian officials contacted by Reuters said they had been instructed not to speak to the media, adding that only the health minister was authorized to comment.
The H5N1 virus remains mainly a virus of birds, but experts fear it could change into a form easily transmitted from person to person and sweep the world, killing millions within weeks or months.
The virus has killed 123 people since late 2003, most of them in Asia, according to the most recent figures from the World Health Organization.
Iran’s neighbors Turkey, Iraq and Azerbaijan have all reported deaths from the virus in recent months.
So far, most human cases can be traced to direct or indirect contact with infected birds.
