below ground. these are the houses that the militants were hiding inside of. you can see what they were doing is they were digging up tunnels so they were able to move from house to house without being seen by the coalition planes. and so that this wasn t spotted from the air, they were hiding the dirt that they were digging up and keeping it inside the houses themselves. if you can come through here, we can show you one of the tunnels leading through. some of these tunnels, we re told, went as far as a kilometer. we re going to go have a look inside. it s not that wide, but it does give you a sense thof them movi in the dark under the ground, out of sight. ramadi fell to isis in may of last year. since then iraqi forces have been battling to reclaim it. the head of iraq s counterterror force told us the liberation of