Sumatran orangutans
Orangutans in the island of Borneo. Reuters

Hundreds of rare Sumatran orangutans in western Indonesia could die "within weeks" if palm oil companies continue to set fires to clear land in peat swamp forests, conservationists have warned.

They believe only 200 of the orangutans are left in Tripa forest on the coast of Aceh province, which is surrounded by palm oil plantations. In the early 1990s, their population stood at 3,000. Most of the endangered primates were forced off the land by forest clearance to make way for palm oil plantations.

Palm oil is used to make everything from lipstick and soap to "clean-burning" fuel.

Sumatran orangutans face the additional risk of being captured or killed by residents. Others perish, either in the fires or of gradual starvation and malnutrition.

"They are just barely hanging on," Ian Singleton, conservation director of the Sumatran Orangutan Conservation Program, told AP. "It is no longer several years away, but just a few months or even weeks before this iconic creature disappears."

"We are currently watching a global tragedy," he said.

There are only 6,600 Sumatran orangutans left in the wild.

The environmental group Rainforest Rescue is working to restore and protect the orangutan habitat in Sumatra and their mission is already starting to show results, according to the group's chief executive.

"Orangutans build nests or platforms out of leaves and branches to sleep in overnight and rest in during the day," Kelvin Davies said.

"The team was enormously encouraged by the direct evidence that an orangutan had been using the rainforest restored through their hard work and the funding provided by generous donors."