The three-hour Pollutant Standards Index (PSI) has dropped further to 168 at 3pm on Friday, with the air quality dropping back into the "unhealthy" range of 101 to 200.

It was 245 an hour earlier. The PSI has been steadily dropping since 401 at noon and 360 at 1pm.

Earlier in the afternoon, Singapore representatives met with Indonesian officials in Jakarta to discuss the severe haze situation, said the National Environment Agency.

At the meeting, Indonesia briefed Singapore of its plans to deal with the fires causing the haze, and to get their agencies to report twice a day to a national task force

In response to a report from the Indonesian Forestry Ministry that Singapore companies may be involved in illegal burning activities, Singapore requested that Indonesia share the names of such errant companies. Singapore also offered Indonesia an assistance package, including an aircraft for cloud seeding operations as well high resolution satellite pictures and hotspot coordinates.

Emeritus Senior Minister Goh Chok Tong had also made a Facebook post in response to the haze earlier in the afternoon. Referring to Indonesia, he urged good neighbourly practices, and said that it was "best to prevent man-made, illegal fires from being started in the first place" because forest and peat fires in Sumatra were difficult to put out.

"But as of now, the Singapore child (had) better learn to survive the tortuous smog and haze," wrote Mr Goh.