JAKARTA, Indonesia (AP) – Smoke from Indonesian brush fires darkened skies across Southeast Asia on Saturday, sending air pollution levels soaring in at least two other nations.

Singapore’s air quality index hit 130, its highest level this year. It was also the first time in 2006 the measurement climbed above 100, the threshold for “unhealthy.”

Farmers or agricultural companies started the fires on Borneo and Sumatra island as a cheap way of clearing the land.

Some hospitals in those parts of Indonesia were crowded with people complaining of difficulty breathing. Flights were cancelled and drivers were having to use their lights in the middle of the day.

Firefighters said the blazes were out of control and only the monsoon rains would put them out. The forecast calls for the rains to begin in the next month.

“We have tried various measures but it is really difficult to stop the fires,” said Marjani Achmad, the head of the forest fire prevention unit in hard-hit Jambi island.

The haze was also cloaking much of Malaysia, where only three of the country’s 51 air quality monitoring stations registered clean air on Friday.

The haze is a perennial problem for the region. The worst case occurred in 1997-98, when smoke from land-clearing in Sumatra blanketed much of the region and was blamed for losses of nearly $9 billion in tourism, health and business.