Malaysia is to begin cloud-seeding operations to try to induce rain to clear the air after a layer of heavy haze forced the closure of schools in four states, including Kuala Lumpur.

The thick, dirty white haze blanketed many parts of Malaysia, with 34 out of 52 air quality stations recording unhealthy air levels.

Meteorological department official Maznorizan Mohamad said two planes will take off later today in Kuala Lumpur and surrounding areas, as well as in Kuching in Sarawak state on Borneo island.

She said the cloud-seeding is planned for three days but will depend on cloud availability and weather conditions.

The haze affects the region every year, and is largely caused by slashing and burning forests to clear land for agriculture in Indonesia.