Campers have joined police to search through the night for the missing boy, who was on a family holiday.
Sergeant Ben Darcy said the search has been "difficult" in the dark but a more extensive hunt was due to start as daylight breaks.
The search has gone on throughout the night but due to the location it has been very difficult to do. It is a heavily wooded area. With the daylight we will be getting more officers in for a more extensive search.
– Sergeant Ben Darcy, Gloucestershire Police
The majority of our campers were helping in the search overnight, and my family. Everyone is very anxious, we're just hoping we are going to find him walking in the woods somewhere. We had an amazing response from the local police last night and an amazing response from the campers.