Some residents of the capital city were left scratching their heads – and plugging their noses – over a foul odour that spread over a large area of the west end and south side on Saturday.

The city of St. John’s says the source of the stench is unknown, and staff at the Riverhead Waste Water Treatment plant reported nothing out of the ordinary at the time.

Residents say the foul smell dissipated within a couple of hours.

The St. John’s Port Authority says it is not aware of any smell coming from the harbour area at that time.