Tanks and tunnels: Khan Yunis, epicentre of Gaza war

Tanks and gunfire continue in Gaza's main southern city of Khan Yunis, the epicentre of the war. The Israeli army leads journalists through a Hamas tunnel in the city, part of the extensive underground network known as the "Gaza Metro". Khan Yunis is the hometown of Hamas's Gaza leader Yahya Sinwar, and the city has suffered heavy bombing and combat.