As a blanket of haze, caused by thick smoke from forest fires in Indonesia, covers parts of South-east Asia, the region is struggling to find an effective response to the problem, experts said.

The haze has caused health problems, flight delays and school closures across Indonesia, Malaysia and Singapore in what has become an annual ordeal that has defied attempts by governments, businesses and green groups to tackle it.

At the heart of the problem are palm oil plantation owners, who use cheap and easy slash-and-burn techniques to clear forests and meet rising global demand for the oil used for cooking and in household products from shampoo to ice cream.

… Ms Margareth Sembiring, senior analyst at Nanyang Technological University in Singapore, said the complexity of the issue means it is difficult to make the region haze-free. “Strengthening law enforcement in Indonesia is undoubtedly key in solving the problem,” she said.