SINGAPORE - A strong burning smell was prevalent in the eastern part of Singapore on Thursday evening.

An ST reader wrote in to say she detected the smell while riding on the MRT from Tanah Merah station towards Pasir Ris.

Twitter user @theGretL claimed it smelt like burning plastic, while readers staying in Siglap, Bedok, Pasir Ris and East Coast Road said they were affected as early as 6.30pm.

As of 9.30pm, the Singapore Civil Defence Force confirmed that there had been no fires reported in the affected areas.

A check on the National Environment Agency's app MyEnv revealed that that the hourly PM2.5 reading in the east peaked at 44 at 9pm, an unusually high reading compared to the other parts of Singapore. It dropped down to 30 at 10pm. The PM2.5 reading for the north, west and central at 9pm hovered at 16 and the south registered 5.

PM2.5 are small, toxic particles that can be emitted by forest fires, vehicles, power plants, refineries, ships and aircraft, and to a lesser extent by construction and land reclamation.

Are you affected? Tell us.