The PSNI in Derry have asked people to be vigilant after the suspicious movements of a black van in the city's northern suburbs were reported to Strand Road.
On Thursday police received a report about suspicious activity in the Carnhill area.
"This report stated that occupants of a vehicle called at a home in the area offering gardening work.
"We are keen to speak to the occupants of this vehicle to verify their legitimacy," a PSNI spokesman said.
Police have asked the occupants of the vehicle to contact them on 101, quoting reference number 1130 of 1/8/19.