A four-year-old girl has died of bird flu in Indonesia, the country hardest hit by the virus, a doctor said Monday.

The girl died last week after she was admitted to Arifin Achmad hospital in Pekanbaru, Riau province, with high fever, the hospital's unit head, Azizman Saad, said.

"She was admitted on Monday and died on Wednesday. We're not sure if she had contact with chickens but the test results confirmed she was infected by the H5N1 virus," he added.

According to the , as of last month H5N1 had killed 292 people across the world since 2003. The official toll for Indonesia stands at 135.

The virus typically spreads from birds to humans through direct contact, but experts fear it could mutate into a form easily transmissible between humans, with the potential to kill millions in a pandemic.