Smoke from Indonesian fires hits 'unhealthy' level in Singapore

Air pollution in Singapore rose to an "unhealthy" level on Friday as acrid smoke drifted over the city from fires on Indonesia's Sumatra Island, the city-state's National Environment Agency said, in repeat of an annual crisis.

Every dry season, smoke from fires set to clear land for palm oil and pulp and paper plantations in Indonesia clouds the skies over much of the region, raising concern about public health and worrying tourist operators and airlines.

Singapore's three-hour air pollution index was at 157 by late afternoon, after peaking at 215. Its environment agency doesn't give a health warning with the limited duration index, but on a 24-hour basis it says levels above 100 are unhealthy and above 200 very unhealthy.