Malaysia's Sarawak state plans cloud seeding operations in early September, officials said Monday, as smoke from fires in neighbouring Indonesia pushes air quality to hazardous levels.Indonesia has for weeks battled wildfires that have led to school closures and thousands of people requiring medical treatment, with smoke also drifting across to Malaysia and Singapore.

Sarawak, which shares a border with Kalimantan province, has been the most affected by the haze.

Sarawak Disaster Management Committee chairman Douglas Uggah Embas said Monday cloud seeding could be carried out between September 3 and 5, if weather and atmospheric conditions permit.

"Cloud seeding can only be carried out when suitable cloud formations and atmospheric conditions are present -- it cannot create rain in the absence of suitable clouds," Uggah told reporters.

Air quality deteriorated sharply across Sarawak on Monday, with seven locations recording hazardous Air Pollutant Index (API) readings above 300, led by Serian district at 475.