G.K. Goh, Jakarta – Smoke from land clearing by fire on Tuesday cast a haze over the skies of several cities in Borneo and Sumatra island, causing eye irritations and breathing problems, officials said.

"Visibility is about 5,000 metres now, but motorists complain of eye irritation," said Kusharyanto of the meteorolgy office in Pontianak, the capital of the Indonesian province of West Kalimantan. He said the pattern remained the same as previous days, with thicker haze in the nights until it is pushed away by winds early in the morning.

Kusharyanto said visibility had been around 500 metres at 6:00 am but had improved to 800 metres an hour later. By 9am, visibility had drastically improved to 5,000 metres. The airport control tower said that unlike Monday, the visibility on Tuesday caused no delays to incoming and departing flights.

The haze which had blanketed Pekanbaru, the capital of the Riau province on Sumatra island, had noticeably thinned compared to Monday, an official of the meteorology office there said.

"It rained early this morning, at around 4:30am, clearing the sky from the haze, said the official who only identified himself as Rasyidin. He said that visibility for the past five hours until 9am had hovered around 3,000 metres.

But the smoke cast a haze over Medan, the capital of North Sumatra province. "The sky has been like this since yesterday, grey and hazy," said Firman from the meteorology office in Medan, adding that visibility at 9am was at around 2,000 metres. He said that though the haze was "visually detectable" it was not thick enough to cause discomfort and irritation.

He also said that flights at the nearby Polonia airport were reportedly unaffected. "Most flights have automatic pilot control, and therefore do not rely on visual approach," Firman said.

The arrival of the haze, coinciding with drier climatic conditions have already prompted meteorolgy offices in Pandang, Jambi and Palembang, all in the lower half of Sumatra island, to be on the look out for the first signs of the smoke.

"We still have good visibility levels here, above 12,000 metres, but the air has been very dry these past days and the sky is not as clear as it usually is, said Emrizal from the meteorolgy office in Padang, West Sumatra.

"We are expecting haze in the coming weeks, as the dry season would mean preparation for the next planting season," Emrizal said.

The dense smoke haze which blanketed parts of Indonesia and its neighbours for months three years ago has been blamed on widespread land clearing by fire in Indonesia. The government has banned land clearing using fire by plantations and other large companies, but it has been helpless in enforcing the ban on small farmers across the country.

Haze has also been reported to have covered some parts of Malaysia and southern Thailand in the past week.

West Kalimantan and Riau were among several Indonesian regions affected by thick smog in 1997-98, which also spilled over to several neighbouring countries, causing extensive health and traffic dangers. The choking haze caused an estimated 9.3 billion dollars in economic losses.