During the offensive on Hamas in Gaza, Israel bombed hundreds of tunnels on the Gaza-Egypt border. Destroying the tunnels – also the main supply route for Gaza's Hamas rulers boycotted by the West – was one of the main goals of Operation Cast Lead that Israel unleashed on Hamas on December 27 The Israeli military estimates that between 60 to 70 per cent of tunnels were destroyed during its bombing campaign, the evidence of which is everywhere one looks along the border.