Officers say that the van was seen with ladders on the top in the Leegomery area on Saturday afternoon.
PCSO Lynn Harris, of the policing team in Arleston & College, said: "We would like to make residents aware of a large white van with ladders on the top which was in the Leegomery Road area on July 15 at approximately 12.20pm."
The police have no further details of the van but say the occupants were two white males.
"The occupants of the vehicle are two white males, one of the males is described as chubby and approximately 15-years old with an Irish accent," said PCSO Harris.
She added: "Please do not accept any work they may offer you."