SINGAPORE, Sept. 5 -- Singapore's air quality improved on Saturday morning, with the western region returning to the moderate range after briefly recording unhealthy levels earlier in the day.

At 9am, the 24-hour Pollutant Standards Index (PSI) - similar to Malaysia's Air Pollution Index - stood at 115 in the central region, while the west recorded 98 and the east 96, The Straits Times reported.

The west had entered the unhealthy range at 102 at 7am, making it the third region in Singapore to breach the 101 threshold since Friday.

The north and south remained in the moderate range, with readings of 83 and 87 respectively.

Singapore's National Environment Agency (NEA) considers PSI readings of 101 to 200 unhealthy and advises people to...