Jakarta – Indonesian forest and ground fires in Sumatra and Borneo island are on the rise again after dissipating in recent rains, satellite images produced by the Indonesia Space Agency showed Friday.

Satellite images dated September 1 showed 43 hotspots in the region of Sumatra and 16 in Kalimantan, the Indonesian part of Borneo island shared with Malaysia and Brunei, said the agency's Muslich Musa Wijaya.

Rain in recent weeks has kept the number of hotspots in the two regions down to between 10 and 20, he said. The hotspots in Sumatra were detected in Riau, South Sumatra and Lampung provinces. In Borneo, the hotspots were mainly detected in West and Central Kalimantan with two in South Kalimantan.

The fires, blamed on farmers and plantation owners clearing their land, have revived fears of haze blanketing neighbouring countries in a repetition of a regional environmental disaster two years ago.

Riau authorities last month called for the closure of schools, especially at nursery and primary levels as forest and scrub fires worsened, saying that youngsters were most vulnerable to the effects of the smog. They have also called on schools to refrain from conducting outdoor activities.

Forest fires have reappeared in the lower half of Sumatra island and several parts of Kalimantan since June. But occasional rain has stopped the haze from reaching the levels it hit in 1997, when huge forest and ground fires during a prolonged drought destroyed more than 10 million hectares of Indonesian forest.

In 1997 and early 1998, the smoke haze covered a wide swathe of skies over Indonesia and neighbouring countries, causing massive economic losses along with serious health problems and visibility hazards to ships and planes.

Indonesia decreed a "zero-burning" policy early this year but it has gone largely unenforced with officials citing a lack of funds and personnel.