Singapore saw its worst air pollution reading of the year as the island was shrouded in haze from Indonesian forest fires.
As of midday local time (0400 GMT) the Pollutant Standards Index (PSI) reading ranged from 60 to 72, according to the government agency for the environment.
A reading between 51 to 100 is in the moderate range.
The reading also carries a health advisory to reduce outdoor activities and prolonged exertion.
The smoky conditions blanketed the island from Thursday.
The haze was a result of "an increase in hotspot activities observed over Sumatra" in the past week, the agency said on its website.
''The current prevailing winds blowing from the southwest or south have transported the haze from fires in southern Sumatra towards Singapore.''
The winds are expected to turn and bring some reprieve, the agency added, but warned that Singapore could still see slightly hazy conditions next week.
Air pollution from Indonesian forest fires has become a recurring problem in the region, especially during this time of year when the southwest monsoon season brings periods of dry weather.
The South East Asian neighbours have been working on measures and regulations to curb the practice of forest burning in Indonesia.
However, activists say that officials have not been hard and fast in enforcing the regulations.