SINGAPORE - A fire in southern Johor, which was the likely cause of the burning smell reported by Singaporeans earlier this week, has been put out, the National Environment Agency (NEA) said on Wednesday (Feb 27).

However, a second hot spot was detected in Johor, about 50km to the east and north-east of Singapore on Tuesday.

The smoke plume from the hot spot was blown south-west by the prevailing north-easterly winds, the environment agency said.

The NEA said in its statement that it received feedback about a burning smell in many parts of Singapore on Tuesday.

Haze and a burning smell may be expected in Singapore if the fires in Johor continue, it added.

On Monday, the NEA said that there was a hot spot in southern Johor, 30km east of Singapore, which was the likely cause of the burning smell that was reported by residents between Sunday evening and Monday morning.

The Department of Environment (Johor) has since informed the NEA that there was a fire at Punggai, near Bandar Penawar, in the vicinity of an oil palm plantation. The fire was due to the hot weather in parts of Johor.

The firemen from Bandar Penawar have managed to put out the fire, after firefighting efforts over the last few days, with the aid of rain on Tuesday, the NEA said.

However, around 20 per cent of the surrounding area remains smoky.

The NEA said that February is normally a dry month for the surrounding region, and extended periods of dry weather can lead to land and vegetation fires.

The Pollutant Standards Index (PSI) across Singapore ranged from 31 to 52, in the "good" to "moderate" range, as at 8pm on Wednesday.

The one-hour PM2.5 readings ranged from 7 to 21 micrograms per cubic metre, which is in the "normal" range. PM2.5 is the dominant pollutant during haze episodes.

The NEA said on Wednesday that members of the public can continue with their normal activities.

"We are closely monitoring the air quality and will provide updates on any significant changes to the air quality situation," the agency said.