POLICE have issued a warning after groups of 'suspicious' people were seen selling items in Southampton.

An officer revealed that reports have been made that men and women were seen knocking on doors in Bitterne attempting to sell kitchen knives.

A police statement said: "Please remember to be extra vigilant and if in doubt ask to see their pedlar's certificate.

"This certificate allows a person to trade whilst on foot.

"If the seller cannot produce a pedlar's certificate, then they are trading illegally and this needs to be reported on 101."