Acehnese refugees forced into camps to escape fighting between Indonesian troops and separatist rebels are suffering health problems due to overcrowding and lack of clean water.
Almost 41,000 people have been moved into the tented camps, sometimes against their will, during the first month of a major offensive to crush the Free Aceh Movement.
"We do not have what in medical terms we would refer to as outbreaks but we have begun to register numerous cases of respiratory problems, skin problems and to a limited extent, diarrhoea," said Media Yulizar of the Aceh health office.
Yulizar, who gave no figures, blamed a very limited clean water supply and packed conditions.
Yulizar said Wednesday that her office had begun conducting regular anti-mosquito spraying in some camps and immunisation programs for younger children. "The latest figure we have is 40,919 refugees sheltered in camps in nine districts," said Burhanuddin, spokesman for the province's social affairs office.
Like many Indonesians, Burhanuddin has just one name. He said more than 16,500 are in Bireuen district, a rebel stronghold, and 10,000 others in South Aceh district.
Burhanuddin said his office is providing rice, noodles, dried fish, cooking oil, canned food, sugar and milk for children and infants as well as tents. Provision of clean water was the responsibility of another office and the local authorities.
Last Friday the military and police moved some 10,000 people from their homes in Jeuli district, just south of Bireuen town, before launching an artillery barrage on a suspected rebel base. The evacuees, some carrying clothes and bedding, were taken to Cot Gapu village east of Bireuen where tents had been prepared on a football field.
"The problem of water for drinking, cooking and washing in Cot Gapu camp is very serious," the UN Office for the Coordination of Humanitarian Affairs said in a report Monday.
"Sanitation problems resulting from the lack of clean water are mounting in the camp." The UN office said refugees also complained of meagre rations, with rice and some noodles or fish the only items available at the time. It said children were suffering from the intense heat in the open or inside crowded tents.
Many refugees at Cot Gapu have demanded to be allowed to return home, the state Antara news agency said.
Refugees said water has become a luxury, including water for ritual ablutions before the five daily Muslim prayers. Antara said there are only 20 lavatories for some 10,000 refugees.
"We wish to go home soon. Nobody is tending our cattle and it would be difficult to resume business after being away for so long. Most of us are small farmers," Antara quoted one refugee there as saying.
Top security minister Susilo Bambang Yudhoyono said Tuesday the number of refugees is expected to rise to 100,000. He said he had ordered local officials "to take good care of the refugees ... to anticipate new humanitarian problems."
Military operation spokesman Yani Basuki, quoted by the Jakarta Post, said the refugees could only leave for their villages once security had been restored. Basuki, who could not be immediately reached for comment, said moving people out of villages was part of efforts to avoid civilian casualties.
GAM has been fighting since 1976 for independence for the province on the northern tip of Sumatra island. More than 10,000 people, mostly civilians, have been killed since then.