An explosion went off early Tuesday at a Hamas training camp in Gaza, killing two members of the group and wounding three, a Palestinian health official and Hamas said. The Israeli military said it was not involved, according to a report of the Associated Press. The blast came during a three-week-old truce between Gaza's Hamas rulers and Israel. A small building collapsed as a result of the explosion in the training camp in southern Gaza. One of the wounded, who was in critical condition, was pulled from the rubble, said Dr. Moaiya Hassanain of the Health Ministry.