THE Pollutant Standards Index in Singapore hit a high of 321 on Wednesday, and on Friday, Nasa released stunning images of the smoke from Sumatra's hotspots being blown to Singapore.

The images were captured on Wednesday by the Moderate Resolution Imaging Spectroradiometer (Modis), an instrument that observes the entire surface of Earth's every 1 to 2 days, wrote Nasa on its Earth Observatory website.

The first image was taken at 11.30am Singapore time, while the second was taken at 2.30pm Singapore time.

The PSI in Singapore has since climbed to new records, hitting 401 at 12pm on Friday.

The full images can be found here.