Both a man and a teenager trying to sell jewelry online were robbed and sprayed with a noxious substance, say Halifax police.

The first attack happened around 9:20 p.m. Tuesday near the corner of Lacomb Drive and Gaston Road in Dartmouth.

Halifax Regional Police said a man, 25, was selling a piece of jewelry on Kijiji, an online classified site. He agreed to meet the buyers – two men – near the intersection to complete the sale.

But once the man gave the pair the jewelry, they sprayed him with the substance and took off.

Police said the man was treated at the scene.

On Wednesday, a teenager said he met two people in the parking lot of the Kent Building Supplies in Lower Sackville just after 6:00 p.m. to sell a piece of jewelry he advertised on the site.

Once he handed over the item, the RCMP said he and his three passengers were sprayed with an unknown substance.

The K9 unit was brought in but the suspects have not been found.