The 'killer' smog that has often plagued Southeast Asia might be coming back.
Fires are burning across central Sumatra, Indonesia, where thousands of people are in respiratory distress and a state of emergency has been declared.
Around 1500 fires, mostly illegal, have been detected in Sumatra's Riau Province alone.
The fires are attributable to an early dry season, rampant land-use change, and little government control over forest burning.
In past years, such fires have blanketed much of Malaysia and Singapore in a dense smog, creating a health hazard for millions of residents--many of whom don face-masks when venturing outside.
The fires are being mostly blamed on forest clearing for oil palm plantations. Indonesia is being faulted for failing to ratify an ASEAN agreement to monitor and combat forest fires and for not publicly releasing maps showing which companies own the lands being burned.