Humberside Police is appealing for witnesses following two indecency incidents on the country roads around the Etton, South Dalton area.
The first incident was on Friday 30 August and the second incident was Saturday 31 August 2013.
In both instances two walkers have seen an unknown a man a few hundred yards ahead stood on the grass verge exposing his lower half in the direction of the walkers.
On one occasion the man started removing his top.
The man is believed to be using a small grey coloured car.
No one has been hurt in the instances.
The area is used by walkers and cyclists and anyone who has seen anything suspicious should contact Humberside Police on 101 quoting log 535 31/08/13.