Following a Palestinian mortar attack, Israeli troops made five separate raids into Palestinian territory. The troops searched for weapons and destroyed buildings and removed crops and vegetation. Israel has also adopted a policy of stationing troops in Palestinian buildings that had served as firing positions for Palestinian gunmen. Most of this activity was for the defense of Israeli settlements in Palestinian territory. The settlements have become the key stumbling block to peace. The settlers claim a great deal of Palestinian territory for Israel. Some of the more radical settlers want to expel all Arabs from the Palestinian territories. The Palestinian radicals want to destroy Israel. North of Tel Aviv, a bomb exploded near a bus station and adjacent to a rail line. There were no injuries, mainly because a Palestinian passing the bus station saw a suspicious package (containing the bomb), picked it up and threw it away from the bus station.