Malaysian authorities are declaring a state of emergency in a southern district where a smoky haze blamed on Indonesian forest fires has triggered one of the country's worst pollution levels.

The worst of the smog has shifted from Singapore to southern Malaysia, where noxious fumes have drifted across the sea this past week from Indonesia's Sumatra island.

The Malaysian government's index for air pollution reached a measurement of 746 on Sunday in the southern district of Muar. It was far above the threshold of 300 for hazardous air quality.

Environment Minister G. Palanivel said authorities would issue instructions for residents to remain indoors and for schools to close.

Singapore reported pollution readings that fluctuated between "moderate" and "unhealthy" classifications Sunday, far below peak measurements recorded Friday.