The bird flu epidemic that is sweeping south-east Asia has now spread to Indonesia, say officials in Jakarta.
The illness is linked to close contact with live chickens
An Indonesian agriculture ministry official said tests had detected a type of avian flu in chicken flocks.
However, it is not yet clear whether it is the same strain of the virus found in six other countries in the region.
Only two countries have confirmed human cases of the disease. The virus has killed six people in Vietnam and been blamed for another death in Thailand.
The Indonesian Government said bird flu had attacked "millions of chickens" in the country, but further investigation was needed.
Agriculture ministry spokesman Hari Priyono told the AFP news agency: "We will have to see first before ordering a massive culling of fowls in infected areas.
"We will have to be certain that the country has been positively infected by the H5N1 strain of the avian influenza before we start such actions."
Local vets say millions of birds have died in both Java and Bali since last October, but some may well have been killed by farmers trying to contain the spread of the disease.
The BBC's Rachel Harvey in Bangkok says that despite the reluctance of government officials in Jakarta to say for certain, it seems highly likely that Indonesia has fallen prey to the same virus which has affected six other countries in the region.
Army joins cull
As efforts continue in Thailand to cull infected chickens, Prime Minister Thaksin Shinawatra has admitted that his government initially kept quiet about its suspicions that avian flu had broken out.
"We have suspected this for about a couple of weeks," he said.
Mr Thaksin told reporters the government had taken precautionary measures, but he had decided not to tell the public until Friday to avoid causing mass panic.
AVIAN FLU ALERT
First jumped "species barrier" from bird to human in 1997
In humans, similar symptoms include fever, sore throat, and cough
Types known to infect humans are influenza A subtypes H5N1 and H9N2
Thailand - Asia's largest poultry exporter - has now brought in the army to speed up the cull, in which chickens are tied up in sacks and buried alive.
Amid growing criticism of its handling of the disease, Thailand has invited other Asian nations hit by the crisis to an emergency summit this week.
European Union and Japanese officials will also be invited to the meeting in Bangkok on Wednesday, as well as the World Health Organization (WHO) and UN food agency.
Several countries have banned imports of poultry from Thailand, including its main customers, Japan and the EU.
AVIAN FLU TIMELINE
Nov 2003 - Thailand reports what it calls chicken cholera
15 Dec - S Korea confirms avian flu outbreak
9 Jan 2004 - UN sends help to Vietnam after avian flu outbreak
11 Jan - First Vietnamese death confirmed as avian flu
13 Jan - Japan confirms avian flu outbreak
15 Jan - Taiwan announces different strain of avian flu
21 Jan - Laos reports suspected chicken cholera
23 Jan - Thailand confirms first human cases of avian flu
23 Jan - Cambodia detects first case in chickens
25 Jan - Indonesia announces outbreak
On Sunday, China announced it was banning chicken imports from Thailand and Cambodia, which has also been hit by a bird flu outbreak.
Two Thai boys are infected, while the death of a 56-year-old Bangkok man who raised fighting cocks is thought to have been caused by the virus.
Avian flu has also affected chickens in Cambodia, Indonesia, Taiwan, Japan, and South Korea - but is not known to have jumped from birds to humans in these countries.
The WHO has warned that the Asian outbreak could mutate and become more dangerous.