All of them are being treated in a hospital in the capital, Jakarta.
At this stage only one of them has been confirmed as suffering from the virus.
Meanwhile, tests carried out in Indonesia have confirmed that a five-year-old girl who died earlier this week did not have the virus.
Health ministry official, I Nyoman Kandun, says Jakarta is not planning to send the girl's blood samples to a laboratory in Hong Kong for confirmation.
No results have yet been announced for another girl, aged two, who also died in Jakarta this week with symptoms of bird flu.
Since July, Indonesia has reported four human deaths from a strain of bird flu known as H5N1.
WHO urges calm
The World Health Organisation say the growing number of people in Indonesia with possible bird flu symptoms does not mean the outbreak is worsening.
The UN health agency has called for calm and says there is still no evidence of bird flu spreading from person to person in Indonesia.
It says it will continue to monitor the situation closely, and the detection of further human cases in Indonesia or elsewhere would not be surprising.
Earlier this week, the Indonesian government gave bird flu "extraordinary incident" priority status.
Among its measures, extraordinary status allows for the forced hospitalisation of suspected bird flu patients.
Indonesia has also launched a vaccination drive for poultry in an attempt to stop the spread of the virus.
The H5N1 strain of bird flu has killed at least 63 people in South East Asia since 2003, the majority of them in Vietnam.
The WHO fears that H5N1 may mutate, acquiring genes from the human influenza virus that would make it highly infectious and lethal to millions in a global pandemic.