The limpet mines used to attack a Japanese-owned oil tanker near the Strait of Hormuz last week bore "a striking resemblance" to similar mines seen in Iran, a U.S. Navy explosives expert said Wednesday. The comments by Cmdr. Sean Kido came as sailors showed reporters pieces of debris and a magnet the Navy says was used to attach an unexploded mine to the hull of the tanker. U.S. authorities say the materials were left behind by Iran's Revolutionary Guard when they spirited away the unexploded mine after the attack in the Gulf of Oman.