More than 40,000 civilians have now moved to refugee camps

Burhanuddin, a spokesman for the social affairs office in Aceh, said there were incidences of respiratory problems and diarrhoea in the most crowded camp, Cot Gapu, in Bireun district.

He told the Jakarta Post newspaper that poor sanitation and a lack of clean water were to blame, and said that despite ongoing fighting around Bireun, many of the refugees were demanding to go home because the situation was so bad.

Almost 42,000 civilians are thought to have fled their homes for tented camps, as a result of the military offensive in the province, which began almost a month ago.

More than 15,000 of these refugees are based in camps in Bireun.

The conflict, against separatist rebels from the Free Aceh Movement (Gam), continued on Wednesday.

Operation spokesman Lieutenant Colonel Yani Basuki said three more rebels were killed in clashes during the day.

The Indonesian army is still working to distinguish rebels from civilians

John Ferdinand, the head of disaster management at the Indonesian Red Cross, told BBC News Online that 178 rebels and civilians had died in the conflict so far.

The military, however, puts the casualty figure at nearly 250.

Gam says the casualties include scores of civilians, a claim the Indonesian authorities deny.

One of the main problems facing the military is trying to differentiate members of Gam from the general population.

The security forces arrested nine local government officials on Tuesday, accusing them of involvement with the rebels.

Military authorities have now said they will screen all public servants in Aceh to weed out Gam supporters.

Blame 'on both sides'

The situation in Aceh was also discussed at the Association of South East Asian Nations (Asean) regional forum in Phnom Penh on Wednesday.

US Secretary of State Colin Powell said that both sides were to blame for the failure of a peace pact meant to put an end to the conflict.

"Unfortunately neither the Indonesian Government nor the Free Aceh Movement fully implemented the provisions of the agreement," Mr Powell was quoted as saying.

The 23-nation meeting called for a peaceful solution to the conflict, but also voiced its support for the Indonesian Government.

The foreign ministers "pledged their support to deny the separatist movement access to means of violence through, among all, preventing arms smuggling into Aceh province," according to a communique.