Louise Williams, Jakarta – The Indonesian Government has warned that forest fires and smoke haze are getting worse, and monsoon rains are expected to be further delayed, while another fatal haze-related shipping accident was reported in Kalimantan.

Extremely dry and hot conditions persisting across most of Indonesia prompted the new warning as smoke haze returned to most parts of Sumatra, closing 13 airports and reducing visibility in central Kalimantan to less than five metres.

"This year's dry season is different from those of previous years. For the first time ever, the dry season is deviating from the normal pattern," said the Environment Minister, Sarwono Kusumaatmadja, on the two-to three-month delay in monsoon rains.

The latest meteorological forecast suggested monsoon rains would not begin until next month, he said. Several days of patchy rain earlier this month were thought to mark the beginning of the wet but very hot and dry weather has returned.

At least four people were reported drowned and another 21 missing after a river ferry collided with a tug in central Kalimantan, where smoke haze had reduced visibility to three to five metres. There were 37 survivors.

Tens of millions of Indonesians, including Jakarta residents, face serious water shortages. Rural villagers have been walking off the land into nearby towns and a successful March harvest appears unlikely.

Environment Ministry officials said thick haze had returned to the Sumatran province of Riau, adjacent to Singapore. Firefighting efforts, including foreign help, were concentrated in Jambi, further south, where visibility has hovered between zero and 100 metres for almost three months.

In Irian Jaya, where starvation and drought-related disease have killed at least 461 people, supply drops by military aircraft continue.