At least 488 inmates used a tunnel to escape Kandahar's Sarposa prison. Justice Minister Habibullah Ghaleb says Afghan security forces should have noticed the tunneling work when they searched a nearby house 2 1/2 months ago, but he also faults Canadian and U.S. troops who had been stationed at the prison.The mud house where insurgents began digging a lengthy tunnel that at least 488 inmates used to flee an Afghan prison had been searched about 2 1/2 months before by security forces who failed to notice anything amiss, authorities said Tuesday.