KUALA LUMPUR, Aug 5, 2009 (AFP) - Malaysia was Wednesday hit with the worst haze levels recorded this year, as smoke from forest fires caused "unhealthy" levels of pollution in six areas.

Environment Department director general Rosnani Ibarahim said hundreds of forest fires were blazing in the Indonesian provinces of Kalimantan and Sumatra, and in Malaysia's Sarawak state on Borneo island.

"Malaysia started to record an increase in hotspot numbers since Sunday due to the dry weather and open burning activities which spread very fast," she told AFP.

The Air Pollutant Index (API) recorded unhealthy levels of between 102 and 137 in six areas on Wednesday morning, including a district of the capital Kuala Lumpur, two in surrounding Selangor state, and three in Sarawak.

The API considers a score of 101-200 to be unhealthy, while 51-100 is moderate.

An official from the Meteorological Services Department said the heavy haze caused visibility levels to fall to 2 kilometers (1.2 miles) in Selangor as well as Malacca, a tourist destination south of the capital.

Farmers in Indonesia and Malaysia's half of Borneo island burn forests every year to clear land for agriculture, sending plumes of smoke across neighbouring countries.

The haze hit its worst level in 1997-1998, costing the Southeast Asian region an estimated nine billion dollars by disrupting air travel and other business activities.