KUALA LUMPUR, Oct. 15 -- Thick transboundary haze continued to blanket Malaysia this morning, pushing exactly half of the nation's air monitoring stations into the unhealthy bracket and leaving not a single area with clean air, according to the Department of Environment (DOE).

Data from the DOE dashboard at 9.30am showed that 34 out of 68 stations registered Air Pollutant Index (API) readings between 101 and 200, marking a steady deterioration from 28 stations yesterday afternoon and 27 yesterday morning.

The remaining 34 stations sat in the moderate tier, while the two stations that still recorded good air quality a day earlier slipped out of the bracket. While no station crossed into the very unhealthy tier above 200, the worst-hit ar...