A six year-old Indonesian girl who died six days ago had bird flu, an official at the health ministry said on Thursday, taking the country´s death toll from the disease to 63.

Indonesia, which has the world´s highest number of human fatalities from bird flu, has been trying to step up efforts to stamp out the disease after a flare up in cases this year following a brief lull.

"There has been another H5N1 fatality case, a six-year old girl from central Java. According to information, her neighbors had dead chickens," said Ahmad Priyatna of the ministry´s bird flu information center.

He said the victim died in a hospital in Yogyakarta last Friday.

Six people have died of the disease this year in Indonesia, where the virus is endemic in poultry in many provinces.

In South Sulawesi province, five people with bird flu symptoms have been hospitalized for testings, a doctor said.

Their health was improving, said Khalid Saleh, a doctor in charge of the bird flu ward at Wahidin Sudirohusodo hospital in the provincial capital, Makassar.

"They come from the same neighborhood. It was said chickens have died in the area," he told Reuters.

Indonesia, the world´s fourth-most-populous country that stretches across 17,000 islands, faces an uphill task in fighting the virus.

Millions of backyard fowl live in close proximity to humans and keeping backyard chickens is ingrained in Indonesia´s culture. Health education campaigns have often been patchy and rules difficult to enforce.

Contact with sick fowl is the most common way people are infected.

Bird flu remains essentially an animal disease. With the latest case, 270 people worldwide have been infected by it since late 2003, killing 164 of them.